AI Hallucination Cases

This database tracks legal decisions1 I.e., all documents where the use of AI, whether established or merely alleged, is addressed in more than a passing reference by the court or tribunal.

Notably, this does not cover mere allegations of hallucinations, but only cases where the court or tribunal has explicitly found (or implied) that a party relied on hallucinated content or material.

As an exception, the database also covers some judicial decisions where AI use was alleged but not confirmed. This is a judgment call on my part.
in cases where generative AI produced hallucinated content – typically fake citations, but also other types of AI-generated arguments. It does not track the (necessarily wider) universe of all fake citations or use of AI in court filings.

While seeking to be exhaustive (608 cases identified so far), it is a work in progress and will expand as new examples emerge. This database has been featured in news media, and indeed in several decisions dealing with hallucinated material.2 Examples of media coverage include:
- M. Hiltzik, AI 'hallucinations' are a growing problem for the legal profession (LA Times, 22 May 2025)
- E. Volokh, "AI Hallucination Cases," from Courts All Over the World (Volokh Conspiracy, 18 May 2025)
- J-.M. Manach, "Il génère des plaidoiries par IA, et en recense 160 ayant « halluciné » depuis 2023" (Next, 1 July 2025) - J. Koebler & J. Roscoe, "18 Lawyers Caught Using AI Explain Why They Did It (404 Media, 30 September 2025)

If you know of a case that should be included, feel free to contact me.3 (Readers may also be interested in this project regarding AI use in academic papers.)

Based on this database, I have developped an automated reference checker that also detects hallucinations: PelAIkan. Check the Reports Report icon in the database for examples, and reach out to me for a demo !

For weekly takes on cases like these, and what they mean for legal practice, subscribe to Artificial Authority.

State
Party
Nature – Category
Nature – Subcategory

Case Court / Jurisdiction Date ▼ Party Using AI AI Tool Nature of Hallucination Outcome / Sanction Monetary Penalty Details Report(s)
Iskenderian v. Southeastern Hawai'i (USA) 23 June 2025 Lawyer Fabricated citations N/A

After other side pointed out that all authorities cited were fictitious, Counsel admitted it in brief. The court seemingly did not react.

Reilly v. Conn. Interlocal Risk Mgmt. Agency D. Connecticut (USA) 20 June 2025 Pro Se Litigant Implied
False Quotes Case Law (1)
Misrepresented Case Law (1)
Warning

"Artificial intelligence may ultimately prove a helpful tool to assist pro se litigants in bringing meritorious cases to the courts. In that way, artificial intelligence has the potential to contribute to the cause of justice. However, accessing any beneficial use of artificial intelligence requires carefully understanding its limitations. For example, if merely asked to write an opposition to an opposing party’s motion or brief, or to respond to a court order, an artificial intelligence program is likely to generate such a response, regardless of whether the response actually has an arguable basis in the law. Where the court or opposing party was correct on the law, the program will very likely generate a response or brief that includes a false statement of the law. And because artificial intelligence synthesizes many sources with varying degrees of trustworthiness, reliance on artificial intelligence without independent verification renders litigants unable to represent to the Court that the information in their filings is truthful."

In re Marriage of Isom and Kareem Illinois CA (USA) 16 June 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Misrepresented Case Law (1)
The appeal was denied, and the trial court's decision was affirmed.
Taylor v. Cooper Power & Lighting Corp. E.D.N.Y. (USA) 13 June 2025 Lawyer Implied One fabricated citation Warning

"In Rutella's reply in support of his motion to vacate, he cites Green v. John H. Streater, Jr., 666 F.2d 119 (3d Cir. 1981). DE [69-1] at 8. When the Court was unable to locate Green or any case resembling it, the Court instructed Rutella's attorney, Kevin Krupnick, to either submit a copy of the case or show cause why he should not be sanctioned. See Electronic Order dated May 22, 2025. Krupnick admitted that he fabricated the Green case and claimed that he used it as a “placeholder” in a draft. DE [70-1]. It is implausible that an attorney would cite a case as specific as “Green v. John H. Streater, Jr., 666 F.2d 119 (3d Cir. 1981)” – which Krupnick admits does not exist – as a “placeholder” that he intended to replace. This is particularly true here, as Plaintiff had already cited the case that he subsequently claimed he intended to use. See DE [69-1] at 3 (citing Peralta v. Heights Med. Ctr., 485 U.S. 80 (1988)). Although Krupnick's conduct raises questions of his adherence to Fed. R. Civ. P. 11 (as he himself concedes), given the Court's recommendation that Rutella's motion to vacate be denied, the Court declines to recommend further action with respect to Rutella's misleading submission. "

Rochon Eidsvig & Rochon Hafer v. JGB Collateral Texas CA (USA) 12 June 2025 Lawyer Implied
Fabricated Case Law (4)
8 mandatory hours of Continuous Legal Education on ethics and AI

"Regardless of whatever resources are used to prepare a party’s brief, every attorney has an ongoing responsibility to review and ensure the accuracy of filings with this and other courts. This includes checking that all case law cited in a brief actually exists and supports the points being made. It is never acceptable to rely on software or technology—no matter how advanced—without reviewing and verifying the information. The use of AI or other technology does not excuse carelessness or failure to follow professional standards.

Technology can be helpful, but it cannot replace a lawyer’s judgment, research, or ethical responsibilities. The practice of law changes with the use of new technology, but the core duties of competence and candor remain the same. Lawyers must adapt to new tools without lowering their standards."

Reed v. Community Health Care W.D. Washington (USA) 10 June 2025 Pro Se Litigant Implied Fabricated citations, false quotes Warning

" Plaintiffs identify fictitious quotes and citations in their briefing to support their arguments. For example, Plaintiffs purport to quote language from S.H. Hold v. United States, 853 F.3d 1056, 1064 (9th Cir. 2017) and Green v. United States, 630 F.3d 1245, 1249 (9th Cir. 2011). (Reed 2, Dkt. No. 23 at 6.) However, the quoted language is nowhere found in those cases. Plaintiffs also cite to a case identified as “Horne v. Potter, 557 F.3d 953, 957 (9th Cir. 2009).” (Id. at 7.) That citation, however, is for a case titled Bell v. The Hershey Company. Plaintiffs appear to acknowledge they offered fictitious citations. (See Reed 2, Dkt. No. 27.) Plaintiffs are cautioned that providing fictitious cases and quotes will lead to sanctions. "

Goins v. Father Flanagan's Boys Home D. Nebraska (USA) 5 June 2025 Pro Se Litigant Implied Fabricated citations and misrepresented authorities Warning

" This Court's local rules permit the use of generative artificial intelligence programs, but all parties, including pro se parties, must certify “that to the extent such a program was used, a human signatory of the document verified the accuracy of all generated text, including all citations and legal authority,” NECivR 7.1(d)(4)(B). The plaintiff's brief contains no such certification, nor does the plaintiff deny using artificial intelligence. See filing 27 at 9.
From the Court's review of the plaintiff's brief, most citations are not hallucinatory. But the plaintiff undeniably cites to cases that do not support the stated legal proposition. For example, the plaintiff asserts that “courts must ‘accept all factual allegations in the complaint as true.’ ” Filing 22 at 3. He attributes the quoted language to Braden v. Wal-Mart Stores, Inc., 588 F.3d 585, 595 (8th Cir. 2009). The quote is a boilerplate recitation of the standard on a motion to dismiss, and any number of cases contain that exact language—but not Braden, the case to which the plaintiff attributed the quote.


The plaintiff characterizes the mismatched citations as “[t]ypographical errors or minor misstatements.” Filing 27 at 9. That may be true for some of the mistakes—for example, the case Foman v. Davis, 371 U.S. 178 (1962) is correctly cited, and it immediately precedes a citation for the nonexistent “Foman v. Arnold,” which might be explained as a typographical error. See filing 22 at 13. But not all the mistakes are so innocent, such as the plaintiff's citation to the nonexistent “Brown v. Maple Tree Homes, Inc.,” purported to be a Nebraska case, the citation to which directs to a Wisconsin Supreme Court decision. Filing 22 at 12. This mistake resembles the hallucinatory citations seen in other cases, and is a mistake the plaintiff had an obligation to correct before filing his brief. See Strong v. Rushmore Loan Mgmt. Servs., LLC, No. 8:24-cv-352, 2025 WL 100904, at *6 (D. Neb. Jan. 15, 2025).


The plaintiff also asserts that while the citations may be erroneous, the statements of law are not. The Court agrees that the plaintiff made no substantive misrepresentations of law, so striking the brief is not the appropriate remedy. However, the plaintiff should take notice of the fact that such conduct, if repeated, could subject him to sanctions, even as a pro se litigant. See Ferris v. Amazon.com Servs., LLC, No. 3:24-cv-304, 2025 WL 1122235, at *2 (N.D. Miss. Apr. 16, 2025); Rubio v. D.C., No. 23-cv-719, 2024 WL 4957373, at *4 (D.D.C. Dec. 3, 2024); Vargas v. Salazar, No. 4:23-CV-4267, 2024 WL 4804091, at *3 (S.D. Tex. Nov. 1, 2024); Martin v. Hawai‘i, No. 24-cv-294, 2024 WL 3877013, at *2 (D. Haw. Aug. 20, 2024)."

Powhatan County School Board v. Skinger et al E.D. Virginia (USA) 2 June 2025 Pro Se Litigant ChatGPT
Fabricated Case Law (37)
Misrepresented Case Law (6)
Relevant motions stricken

"The pervasive misrepresentations of the law in Lucas' filings cannot be tolerated. It serves to make a mockery of the judicial process. It causes an enormous waste of judicial resources to try to find cited cases that do not exist and to determine whether a cited authority is relevant or binding, only to determine that most are neither.

In like fashion, Lucas' adversaries also must run to ground the nonexistent cases or address patently irrelevant ones. The adversaries must thus incur needless legal fees and expenses caused by Lucas' pervasive citations to nonexistent or irrelevant cases.

[...]

However, as previously noted Lucas appears to be judgment proof so monetary sanctions likely will not deter her from the abusive practices reflected in her filings and in her previously announced, consistently followed, abuse of the litigation proceedings created by the Individuals with Disabilities Education Act, 20 U.S.C. § 1400, et seq. (“IDEA”). So, the Court must find some other way to protect the interests of justice and to deter Lucas from the abuses which have come to mark her approach to participation as a defendant in the judicial process.

In this case, the most appropriate remedy is to strike Lucas' filings where they are burdensome by virtue of volume and exceed permitted page limits, where they are not cogent or understandable (when given the generous latitude afforded pro se litigants), and where they misrepresent the law by citing nonexistent or utterly irrelevant cases."

In a subsequent Opinion, the court declined to reconsider or review its findings, pointing out that:

"To begin, it is unclear what Lucas means by "contested" citations. The citations that the Court found to not exist are not "contested." They simply do not exist. There is no contesting that fact because the Court checked each citation that was referenced in its MEMORANDUM OPINION, exactly as Lucas cited them (and through other research means), and could not find any citation that matched what Lucas cited. That research demonstrates that the Court's

findings are, in fact, supported rather than "[u]nsupported." Id.

Then, in no way did the Court "wrongly assume[]" that these citations to nonexistent legal authority were "'fabricated' due to the use of generative AI." Id. The Court meticulously checked every citation that it held did not exist in those decisions. Those decisions were not based on "assumptions" but, instead, on the fact that either (1) no case existed under the reporter citation, case name, or quotation that Lucas used, or (2) a case with the reporter citation did exist but was to an entirely different case than the one cited by Lucas and had no relevancy to the issues of this case. ECF No. 170, at 520. And, there was no incorrect assumption that those nonexistent legal authorities were generated, hallucinated, or fabricated by AI because Lucas admitted, on the record, to using AI when writing her filings with the Court. The fact that her citations to nonexistent legal authority are so pervasive, in volume and in location throughout her filings, can lead to only one plausible conclusion: that an AI program hallucinated them in an effort to meet whatever Lucas' desired outcome was based on the prompt that she put into the AI program. As the Court described in its MEMORANDUM OPINION, this is becoming an alarmingly prevalent occurrence common

to AI programs. Id. at 23-26. It is exceedingly clear that it occurred here.

[...]

The MOTION also complains that the Court did not give Lucas an "opportunity to verify or correct citations." Id.

Wholly apart from the fact that it is the litigant's (pro se or represented) burden to verify citations, there is no reason to have accorded Lucas the opportunity to verify because the problem was extensive and pervasive across at least six filings. Moreover, the Court actually did what should have been done before the MOTION was filed by determining that those citations do not exist. No further verification is necessary. And, after a diligent search, if the Court could not find the legal authorities that Lucas purported to rely upon and present as real and binding, it is a folly to believe that Lucas' efforts at "correction" would have returned anything different. Further, she could have taken the opportunity in this MOTION to go through—citation by citation—and "verify" or "correct" them to demonstrate to the Court that its findings were, in fact, incorrect, rather than just baldly and without evidence claiming them to be so. She did not do that."

Andersen v. Olympus as Daybreak D. Utah (USA) 30 May 2025 Pro Se Litigant Implied Fabricated citations and misrepresentation of past cases Warning

In an earlier decision, the court had already warned the plaintiff against "any further legal misrepresentations in future communications".

Delano Crossing v. County of Wright Minnesotta Tax Court (USA) 29 May 2025 Lawyer Unidentified
Fabricated Case Law (1)
Misrepresented Case Law (1), Legal Norm (2)
Breach of Rule 11, but no monetary sanction warranted; referred counsel to Lawyers Professional Responsibility Board

AI Use

Attorneys for Wright County submitted a memorandum in support of a motion for summary judgment that contained five case citations generated by artificial intelligence; these citations did not refer to actual judicial decisions. Much of the brief appeared to be AI-written. The attorney who signed and filed the brief, acknowledged that the cited authorities did not exist and that much of the brief was drafted by AI.

Ruling/Sanction

The Court found Counsel's conduct violated Rule 11.02(b) of the Minnesota Rules of Civil Procedure, as fake case citations cannot support any legal claim and there's an affirmative duty to investigate the legal underpinnings of a pleading. The Court found no merit in Counsel's defense, noting that the substitute cases she offered did not support the legal contentions in the brief, and the brief demonstrated a fundamental misunderstanding of legal standards. The Court did not find her insinuation that another, accurate motion document existed to be credible.

Although the Court considered summarily denying the County's motion as a sanction, it ultimately denied the motion on its merits in a concurrent order because the arguments were so clearly incorrect.

The Court declined to order further monetary sanctions, believing its Order to Show Cause and the current Order on Sanctions were sufficient to deter Counsel from relying solely on AI for case citations or legal conclusions in the future. However, the Court referred the matter concerning Counsel's conduct to the Minnesota Lawyers Professional Responsibility Board for further review, as the submission of an AI-generated brief with fake citations raised questions regarding her honesty, trustworthiness, and fitness as a lawyer.

Anita Krishnakumar et al. v. Eichler Swim and Tennis Club CA SC (USA) 29 May 2025 Lawyer Implied
Fabricated Case Law (2)
Argument lost on the merits in tentative ruling

The underlying motion was later withdrawn, with the result that the tentative ruling was not adopted.

Mid Cent. Operating Eng'rs Health v. Hoosiervac S.D. Ind. (USA) 28 May 2025 Lawyer Unidentified
Fabricated Case Law (3)
Monetary Sanction 6000 USD

(Earlier report and recommendation can be found here.)

AI Use

Counsel admitted at a show cause hearing that he used generative AI tools to draft multiple briefs and did not verify the citations provided by the AI, mistakenly trusting their apparent credibility without checking.

Hallucination Details

Three distinct fake cases across filings. Each was cited in a separate brief, with no attempt at Shepardizing or KeyCiting.

Ruling/Sanction

The Court recommended a $15,000 sanction ($5,000 per violation), with the matter referred to the Chief Judge for potential additional professional discipline. Counsel was also ordered to notify Hoosiervac LLC’s CEO of the misconduct and file a certification of compliance.

Eventually, the court fined Counsel $6,000, stressing that this was sufficient.

Key Judicial Reasoning

The judge stressed that "It is one thing to use AI to assist with initial research, and even nonlegal AI programs may provide a helpful 30,000-foot view. It is an entirely different thing, however, to rely on the output of a generative AI program without verifying the current treatment or validity—or, indeed, the very existence—of the case presented. Confirming a case is good law is a basic, routine matter and something to be expected from a practicing attorney. As noted in the case of an expert witness, an individual's "citation to fake, AI-generated sources . . . shatters his credibility." See Kohls v. Ellison, No. 0:24-cv-03754-LMP-DLM, Doc. 46 at *10 (D. Minn. Jan. 10, 2025)."

Brick v. Gallatin County D. Montana (USA) 27 May 2025 Pro Se Litigant Implied Fabricated citations Warning
Concord v. Anthropic N.D. California (USA) 23 May 2025 Expert Claude.ai Fabricated attribution and title for (existing) article Part of brief was struck; court took it into account as a matter of expert credibility

Counsel's explanation of what happened can be found here.

Source: Volokh
Luther v. Oklahoma DHS W.D. Oklahoma (USA) 23 May 2025 Pro Se Litigant Implied Fabricated citations Warning

" The Court has serious reason to believe that Plaintiff used artificial intelligence tools to assist in drafting her objection. While the use of such tools is not prohibited, artificial intelligence often cites to legal authorities, like Cabrera, that do not exist. Continuing to cite to non-existent cases will result in sanctions up to and including dismissal. "

Rotonde v. Stewart Title Insurance Company New York (USA) 23 May 2025 Pro Se Litigant Implied Fabricated citations Warning
Garner v. Kadince Utah C.A. (USA) 22 May 2025 Lawyer ChatGPT
Fabricated Case Law (1)
1000 USD

AI Use

The fabricated citations originated from a ChatGPT query submitted by an unlicensed law clerk at Petitioner's law firm. Neither Counsel reviewed the petition’s contents before filing. The firm had no AI use policy in place at the time, though they implemented one after the order to show cause was issued.

Hallucination Details

Chief among the hallucinations was Royer v. Nelson, which Respondents demonstrated existed only in ChatGPT’s output and in no official database. Other cited cases were also inapposite or unverifiable. Petitioner’s counsel admitted fault and stated they were unaware AI had been used during drafting.

Ruling/Sanction

The court issued three targeted sanctions:

  • Attorney fees: Respondents’ counsel are to submit an itemized bill; Counsel must pay within 10 days of receipt
  • Client refund: Petitioner’s counsel must refund all fees paid by Mr. Garner in relation to the defective petition
  • Charitable payment: Counsel must donate $1,000 to “and Justice for all” within 14 days and file proof of payment with the court

Key Judicial Reasoning

The panel (Per Curiam) emphasized that the conduct, while not malicious, still diverted judicial resources and imposed unnecessary burdens on the opposing party. Unlike Mata or Hayes, the attorneys in this case quickly admitted the issue and cooperated, which the court acknowledged. Nonetheless, the submission of fabricated law—especially under counsel's signature—breaches core duties of candor and verification, warranting formal sanctions. The court warned that Utah’s judiciary cannot be expected to verify every citation and must be able to trust lawyers to do so

Zherka v. Davey et al. Massachusetts (USA) 22 May 2025 Pro Se Litigant Unidentified Fabricated citations Motion struck, with leave to refile

After being ordered to show cause, plaintiff admitted having used AI for several filings.

Evans et al v. Robertson et al (1) E.D. Michigan (USA) 21 May 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Misrepresented Case Law (1)
Warning
Bauche v. Commissioner of Internal Revenue US Tax Court (USA) 20 May 2025 Pro Se Litigant Implied Nonexistent cases Warning

" While in our discretion we will not impose sanctions on petitioner, who is proceeding pro se, we warn petitioner that continuing to cite nonexistent caselaw could result in the imposition of sanctions in the future. "

Versant Funding v. Teras Breakbulk Ocean Navigation Enterprises S.D. Florida (USA) 20 May 2025 Lawyer Unidentified
Fabricated Case Law (1)
Joint and several liability for Plaintiff’s attorneys' fees and costs incurred in addressing the hallucinated citation; CLE requirement on AI ethics; Monetary fines 1500 USD

AI Use

First Counsel, who had not previously used AI for legal work, used an unspecified AI tool to assist with drafting a response. He failed to verify the citation before submission. Second Counsel, as local counsel, filed the response without checking the content or accuracy, even though he signed the document.

Second Counsel then said that he had initiated "procedural safeguards to prevent this error from happening again by ensuring he, and local counsel, undertake a comprehensive review of all citations and arguments filed with this and every court prior to submission to ensure their provenance can be traced to professional non-AI sources."

Hallucination Details

The hallucinated case was cited as controlling Delaware authority on privilege assignments. When challenged by Plaintiff, Defendants initially filed a bare withdrawal without explanation. Only upon court order did they disclose the AI origin and acknowledge the error. Counsel personally apologized to the court and opposing counsel.

Ruling/Sanction

Judge William Matthewman imposed a multi-part sanction:

  • Attorneys’ fees and costs incurred by Plaintiff in rebutting the hallucinated citation—jointly payable by Counsel
  • Required CLE on AI ethics within 30 days, with proof of completion due by June 20, 2025
  • Monetary fines: $1,000 (First Counsel) and $500 (Second Counsel), payable to the Court registry

The Court emphasized that the submission of hallucinated citations—particularly when filed and signed by two attorneys—constitutes reckless disregard for procedural and ethical obligations. Though no bad faith was found, the conduct was sanctionable under Rule 11, § 1927, the Court’s inherent authority, and local professional responsibility rules.

Key Judicial Reasoning

The Court distinguished this case from more egregious incidents (O’Brien v. Flick, Thomas v. Pangburn) because the attorneys admitted their error and did not lie or attempt to cover it up. However, the delay in correction and failure to check the citation in the first place were serious enough to warrant monetary penalties and educational obligations.

Gjovik v. Apple Inc. N.D. California (USA) 19 May 2025 Pro Se Litigant Unidentified Fabricated citation(s) No sanctions imposed, but warning issued
Source: Jesse Schaefer
Keaau Development Partnership LLC v. Lawrence Hawaii ICA (USA) 15 May 2025 Lawyer Implied
Fabricated Case Law (1)
Monetary sanction against counsel personally; no disciplinary referral 100 USD

AI Use

Counsel filed a motion to dismiss appeal that cited “Greenspan v. Greenspan, 121 Hawai‘i 60, 71, 214 P.3d 557, 568 (App. 2009).” The court found that:

  • No Hawai‘i case titled Greenspan v. Greenspan exists
  • The citations to “121 Hawai‘i 60” and “214 P.3d 568” were in fact to other real cases (Estate of Roxas v. Marcos and Colorado Court of Appeals cases), suggesting a garbled AI-generated fabrication
  • Counsel admitted delegating the brief to a per diem attorney and failing to verify the citation before filing

Ruling/Sanction

  • $100 sanction imposed on counsel personally
  • Payment to be made to the Supreme Court Clerk of Hawai‘i within seven days
  • DiPasquale ordered to file a declaration attesting to payment.

The amount reflects counsel’s candor and corrective measures, but the court noted that federal courts have imposed higher sanctions in similar cases.

Beenshoof v. Chin W.D. Washington (USA) 15 May 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
No sanction imposed; court reminded Plaintiff of Rule 11 obligations

AI Use

The plaintiff, proceeding pro se, cited “Darling v. Linde, Inc., No. 21-cv-01258, 2023 WL 2320117 (D. Or. Feb. 28, 2023)” in briefing. The court stated it could not locate the case in any major legal database or via internet search and noted this could trigger Rule 11 sanctions if not based on a reasonable inquiry. The ruling cited Saxena v. Martinez-Hernandez as a cautionary example involving AI hallucinations, suggesting the court suspected similar conduct here.

USA v. Burke M.D. Florida (USA) 15 May 2025 Lawyer Westlaw's AI tools, GPT4.5 Deep Research (Pro)
False Quotes Case Law (13), Doctrinal Work (3)
Misrepresented Case Law (4), Doctrinal Work (1)
Motion dismissed, and plaintiff ordered to refile it without fake citations.

Counsel later explained how the motion came to be: see here.

Ramirez v. Humala E.D.N.Y. (USA) 13 May 2025 Paralegal Unidentified Four fabricated federal and state case citations Monetary sanction jointly imposed on counsel and firm; order to inform client 1000 USD

AI Use

A paralegal used public search tools and unspecified “AI-based research assistants” to generate legal citations. The resulting hallucinated cases were passed to Counsel, who filed them without verification. Four out of eight cited cases were found to be fictitious:

  • London v. Polish Slavic Fed. Credit Union, No. 19-CV-6645
  • Rosario v. 2022 E. Tremont Hous. Dev. Fund Corp., No. 21-CV-9010
  • Paniagua v. El Gallo No. 3 Corp., No. 22-CV-7073
  • Luna v. Gon Way Constr., Inc., No. 20-CV-893

Ruling/Sanction

The court imposed a $1,000 sanction against Counsel and her firm. Counsel was ordered to serve the sanction order on her client and file proof of service. The court declined harsher penalties, crediting her swift admission, apology, and internal reforms.

Key Judicial Reasoning

The court found subjective bad faith due to the complete absence of verification. It cited a range of other AI-related sanction decisions, underscoring that even outsourcing to a “diligent and trusted” paralegal is not a defense when due diligence is absent.

Source: Volokh
In re Thomas Grant Neusom M.D. Florida (USA) 8 May 2025 Lawyer Unidentified Multiple fictitious or misrepresented case citations Suspension from practice before the Middle District of Florida for one year; immediate prohibition on accepting new federal matters; conditional reinstatement

(Grievance Committee Report available here.)

AI Use

Neusom told the grievance committee that he “may have used artificial intelligence” in preparing filings, and that any hallucinated cases were not deliberately fabricated but may have come from AI tools. The filings in question included a notice of removal and a motion for summary judgment. The judge later noted a pattern of citations inconsistent with established case law and unsupported by known databases.

Hallucination Details

Citations included cases that either did not exist or were grossly mischaracterized. Notably:

  • Southern Specialties, Inc. v. Pulido Produce, Inc. – no such case found in Westlaw, Lexis, or PACER
  • Trilogy Communications v. Times Fiber – cited in support of breach of contract when it was a patent matter involving no such principles

Neusom failed to produce the full texts of the cited cases when requested and instead filed a 721-page exhibit in violation of court orders.

Ruling/Sanction

The court adopted the grievance committee’s recommendation and imposed a one-year suspension. Neusom is prohibited from accepting new federal cases in the Middle District of Florida during the suspension and must:

  • Notify existing clients and the court of his suspension
  • File a compliance affidavit within 30 days
  • Complete appropriate CLE and counseling programs
  • Remain in good standing with the Florida Bar
  • Apply for reinstatement only after certifying compliance

Key Judicial Reasoning

The court found that Neusom violated Rules 4-1.3, 4-3.3(a)(3), 4-3.4(c), and 4-8.4(c) of the Florida Rules of Professional Conduct. His failure to verify AI-generated content, compounded by noncompliance with orders and false statements to opposing counsel, demonstrated a pattern of recklessness and dishonesty. The court emphasized that federal proceedings require a high standard of diligence and that invoking AI cannot excuse failure to meet professional obligations.

Matter of Raven Investigations & Security Consulting B-423447 GAO (USA) 7 May 2025 Pro Se Litigant Unidentified Multiple fabricated citations to prior GAO decisions Warning

AI Use

GAO requested clarification after identifying case citation irregularities. The protester confirmed that their representative was not a licensed attorney and had relied on a combination of public tools, AI-based platforms, and secondary summaries, which produced fabricated or misattributed citations.

Hallucination Details

Examples included:

  • GAO B-numbers with no corresponding decision
  • CPD citations that did not match the referenced holding
  • Alleged direct quotations not found in any GAO decision

The fabrications mirrored patterns typical of AI hallucinations.

Ruling/Sanction

Although the protest was dismissed on academic grounds, GAO addressed the citation misconduct. It did not impose sanctions in this case but warned that future submission of non-existent authority could lead to formal disciplinary action—including dismissal, cost orders, and bar referrals (in the case of attorneys).

Lacey v. State Farm General Insurance C.D. Cal (USA) 6 May 2025 Lawyer CoCounsel, Westlaw Precision, Google Gemini
Fabricated Case Law (2)
False Quotes Case Law (4)
Striking of briefs; denial of requested discovery relief; Large monetary sanctions jointly and severally against the two law firms 31100 USD

AI Use

Counsel used CoCounsel, Westlaw’s AI tools, and Google Gemini to generate a legal outline for a discovery-related supplemental brief. The outline contained hallucinated citations and quotations, which were incorporated into the filed brief by colleagues at both Ellis George and K&L Gates. No one verified the content before filing. After the Special Master flagged two issues, counsel refiled a revised brief—but it still included six AI-generated hallucinations and did not disclose AI use until ordered to respond.

Hallucination Details

At least two cases did not exist at all, including a fabricated quotation attributed to Booth v. Allstate Ins. Co., 198 Cal.App.3d 1357 (1989). Misquoted or fabricated quotes attributed to National Steel Products Co. v. Superior Court, 164 Cal.App.3d 476 (1985). Several additional misquotes and garbled citations across three submitted versions of the brief. Revised versions attempted to silently “fix” errors without disclosing their origin in AI output.

Ruling/Sanction

The Special Master (Judge Wilner) struck all versions of Plaintiff’s supplemental brief, denied the requested discovery relief, and imposed:

  • $26,100 in fees to reimburse Defendant for Special Master costs
  • $5,000 in additional attorney’s fees to Defendant
  • Total monetary sanction: $31,100, payable jointly and severally by Ellis George LLP and K&L Gates LLP
  • No sanctions against individual attorneys due to candid admissions and remedial action, but strong warning issued

Key Judicial Reasoning

The submission and re-submission of AI-generated material without verification, especially after warning signs were raised, was deemed reckless and improper. The court emphasized that undisclosed AI use that results in fabricated law undermines judicial integrity. While individual attorneys were spared, the firms were sanctioned for systemic failure in verification and supervision. The Special Master underscored that the materials nearly made it into a judicial order, calling that prospect “scary” and demanding “strong deterrence.”

Rotonde v. Stewart Title Insurance Co NY SC (USA) 6 May 2025 Pro Se Litigant Implied Several non-existent legal citations Motion to dismiss granted in full; no sanction imposed, but court formally warned plaintiff

AI Use

The court observed that “some of the cases that plaintiff cites… do not exist,” and noted it had “tried, in vain,” to find them. While no explicit AI use is admitted by the plaintiff, the pattern and specificity of the fabricated citations are characteristic of LLM-generated hallucinations.

Ruling/Sanction

The court dismissed all five causes of action—including negligence, tortious interference, aiding and abetting fraud, declaratory judgment, and breach of implied covenant of good faith and fair dealing—as either untimely or duplicative/deficient on the merits. It declined to impose sanctions but explicitly invoked Dowlah v. Professional Staff Congress, 227 AD3d 609 (1st Dept. 2024), and Will of Samuel, 82 Misc 3d 616 (Sur. Ct. 2024), to warn plaintiff that any future citation of fictitious cases would result in sanctions.

Key Judicial Reasoning

Justice Jamieson noted that while the court is “sensitive to plaintiff's pro se status,” that does not excuse disregard of procedural rules or the submission of fictitious citations. The court emphasized that its prior decision in related litigation in 2022 undermined plaintiff’s tolling claims, and that Executive Order extensions during the COVID-19 pandemic did not rescue otherwise-expired claims. The hallucinated citations failed to salvage plaintiff’s fraud and tolling theories, and their use was treated as an aggravating—though not yet sanctionable—factor.

X v. Board of Trustees of Governors State University N.D. Illinois (USA) 6 May 2025 Pro Se Litigant Implied One fabricated citation Warning

"For that principal [sic] [X] cites a case, Gunn v. McKinney, 259 F.3d 824, 829 (7th Cir. 2001), which neither defense counsel nor the Court has been able to locate. The Court reminds [X] that Federal Rule of Civil Procedure 11 applies to pro se litigants, and sanctions may result from such conduct, especially if the citation to Gunn was not merely a typographical or citation error but instead referred to a non-existent case. By presenting a pleading, written motion, or other paper to the Court, an unrepresented party acknowledges they will be held responsible for its contents. See Fed. R. Civ. P. 11(b)."

Harris v. Take-Two Interactive Software D. Colorado (USA) 6 May 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
False Quotes Case Law (1)
Warning

Court held that: "The use of fictitious quotes or cases in filings may subject a party, including a pro se party, to sanctions pursuant to Federal Rule of Civil Procedure 11 as “pro se litigants are subject to Rule 11 just as attorneys are.”

Flowz Digital v. Caroline Dalal C.D. Cal (USA) 5 May 2025 Lawyer Lexis+AI
Fabricated Case Law (1)
Misrepresented Case Law (2)
Order to show cause

In their Response to the Order to show Cause, Counsel specified that they used Lexis+AI, and stressed that "LexisNexis itself has publicly emphasized the reliability of its Lexis+ AI platform, marketing it as providing “hallucination-free legal citations” specifically to avoid citation errors."
Case was eventually jointly dismissed.

Wilt v. Department of the Navy E.D. Texas (USA) 2 May 2025 Pro Se Litigant Unidentified
Fabricated Case Law (2)
Warning
Source: Jesse Schaefer
Gustafson v. Amazon.com D. Arizona (USA) 30 April 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Misrepresented Exhibits or Submissions (1)
Warning
Moales v. Land Rover Cherry Hill D. Connecticut (USA) 30 April 2025 Pro Se Litigant Unidentified
Misrepresented Case Law (1), Legal Norm (4)
Plaintiff warned to ensure accuracy of future submissions

AI Use

The court stated that “Moales may have used artificial intelligence in drafting his submissions,” citing widespread concerns over AI hallucination. It noted that several citations in his complaint and show-cause response were plainly incorrect or irrelevant. While Moales did not admit AI use, the court cited Strong v. Rushmore Loan Mgmt. Servs., 2025 WL 100904 (D. Neb.) and Mata v. Avianca to contextualize its concern.

Hallucination Details

Cited Ernst & Ernst v. Hochfelder, 425 U.S. 185 (1976), and S.E.C. v. W.J. Howey Co., 328 U.S. 293 (1946) as supporting the existence of a federal common law fiduciary duty—an inaccurate legal proposition. The court characterized such misuses as “the norm rather than the exception” in Moales’s submissions. It stopped short of identifying all misused authorities but made clear that the inaccuracies were pervasive.

Ruling/Sanction

The complaint was dismissed for lack of subject matter jurisdiction under Rule 12(h)(3). Moales was permitted to file an amended complaint by May 28, 2025, but was warned that future filings must be factually and legally accurate. The court declined to reach the venue issue or impose immediate sanctions but warned Moales that misrepresentation of law may violate Rule 11.

Key Judicial Reasoning

The court found no basis for federal question jurisdiction and rejected Moales’s reliance on the Declaratory Judgment Act, constructive trust theories, and a nonexistent “federal common law of securities.” It also held that Moales failed to plausibly allege the amount in controversy necessary for diversity jurisdiction.

Willis v. U.S. Bank National Association as Trustee, Igloo Series Trust N.D. Texas, Dallas Division (USA) 28 April 2025 Pro Se Litigant Implied Fabricated citation(s) Warning
Source: Jesse Schaefer
Benjamin v. Costco Wholesale Corp E.D.N.Y. (USA) 24 April 2025 Lawyer ChatOn Five fabricated case citations, and quotations Monetary sanction; public reprimand; order to serve client with decision; no disciplinary referral due to candor and remediation 1000 USD

AI Use

Counsel used ChatOn to rewrite a reply brief with case law, under time pressure, without verifying the outputs. The five cases did not exist; citations were entirely fictional. Counsel later admitted this in a sworn declaration and at hearing, describing her actions as a lapse caused by workload and inexperience with AI.

Hallucination Details

Fabricated cases included:

  • Klein v. E.I. Du Pont de Nemours & Co., 406 F.2d 1004 (cited case does not exist)
  • Gordon v. N.Y. Cent. R.R. Co., 202 F. Supp. 2d 290
  • Mitchell v. JCG Industries, 2010 WL 11627832
  • Hollander v. Sweeney, 2005 WL 19904045
  • Davis v. S. Farm Bureau Cas. Ins. Co., 2019 WL 3452601

None of these cases matched any legal source. Counsel filed them as part of a sworn statement under penalty of perjury.

Ruling/Sanction

The court imposed a $1,000 sanction payable to the Clerk; ordered the counsel to serve the order on her client and file proof of service. The court acknowledged her sincere remorse and remedial CLE activity, but emphasized the seriousness of submitting hallucinated cases under oath. Sanctions were tailored for deterrence, not punishment.

Key Judicial Reasoning

Quoting Park v. Kim and Mata v. Avianca, the court held that submitting legal claims based on nonexistent authorities without checking them constitutes subjective bad faith. Signing a sworn filing without knowledge of its truth is independently sanctionable. Time pressure is not a defense. Lawyers cannot outsource core duties to generative AI and disclaim responsibility for the results.

Nichols v. Walmart S.D. Georgia (USA) 23 April 2025 Pro Se Litigant Implied Multiple fictitious legal citations Case dismissed for lack of subject matter jurisdiction and as a Rule 11 sanction for bad-faith submission of fabricated legal authorities

AI Use

Plaintiff submitted a motion to disqualify opposing counsel that cited multiple non-existent cases. She offered no clarification about how the citations were obtained or whether she had attempted to verify them. The court noted this failure and declined to excuse the misconduct, though it stopped short of attributing it directly to AI tools.

Hallucination Details

The court reviewed Plaintiff’s motion and found that some of the cited cases did not exist. Despite being ordered to show cause, Plaintiff responded only with general statements about her good faith and complaints about perceived procedural unfairness, without addressing the origin or verification of the fake cases.

Ruling/Sanction

The court dismissed the case for lack of subject matter jurisdiction and independently dismissed it as a sanction for bad-faith litigation under Rule 11. It found Plaintiff’s conduct—submitting fictitious legal authorities and refusing to take responsibility for them—warranted dismissal, even if monetary sanctions were not appropriate. The court cited Mata v. Avianca, Morgan v. Community Against Violence, and O’Brien v. Flick as relevant precedents affirming the sanctionability of hallucinated case law.

Key Judicial Reasoning

Judge Hall held that Plaintiff’s conduct went beyond excusable error. Her submission of fabricated cases, refusal to explain their origin, and attempts to shift blame to perceived procedural grievances demonstrated bad faith. The court concluded that dismissal—though duplicative of the jurisdictional ground—was warranted as a standalone sanction to deter future abuse by similarly situated litigants.

Brown v. Patel et al. S.D. Texas (USA) 22 April 2025 Pro Se Litigant Unidentified
Fabricated Case Law (1)
Misrepresented Case Law (2)
Warning

Although no immediate sanctions were imposed, Magistrate Judge Ho explicitly warned Plaintiff that future misconduct of this nature may violate Rule 11 and lead to consequences.

Ferris v. Amazon.com Services N.D. Mississippi (USA) 16 April 2025 Pro Se Litigant ChatGPT 7 fictitious cases Plaintiff ordered to pay Defendant’s reasonable costs related to addressing the fabricated citations

AI Use

Mr. Ferris admitted at the April 8, 2025 hearing that he used ChatGPT to generate the legal content of his filings and even the statement he read aloud in court. The filings included at least seven entirely fictitious case citations. The court noted the imbalance: it takes a click to generate AI content but substantial time and labor for courts and opposing counsel to uncover the fabrications.

Hallucination Details

The hallucinated cases included federal circuit and district court decisions, complete with plausible citations and jurisdictional diversity, crafted to lend credibility to Plaintiff’s intellectual property and employment-related claims. These false authorities were submitted both in the complaint and in opposition to Amazon’s motion to dismiss.

Ruling/Sanction

The court found a Rule 11 violation and, while initially inclined to dismiss the case outright, chose instead to impose a compensatory monetary sanction. Amazon is entitled to submit a detailed affidavit of costs directly attributable to rebutting the false citations. The final monetary amount will be set in a subsequent order.

Key Judicial Reasoning

Judge Michael P. Mills condemned the misuse of generative AI as a serious threat to judicial integrity. Quoting Kafka (“The lie made into the rule of the world”), the court lamented the rise of “a post-truth world” and framed Ferris as an “avatar” of that dynamic. Nevertheless, it opted for the least severe sanction consistent with deterrence and fairness: compensatory costs under Rule 11.

Sims v. Souily-Lefave D. Nevada (USA) 15 April 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Warning
Crystal Truong, et al. v. Flint Hills Resources, LLC, et al. S.D. Texas (USA) 14 April 2025 Lawyer ChatGPT Fabricated citation(s), misrepresented precedents Show cause order; CLE commitment

After explaining what happened (document) counsel opted to non-suit all remaining claims, which means that the court never ruled on the show cause proceedings.

Bevins v. Colgate-Palmolive Co. E.D. Pa. (USA) 10 April 2025 Lawyer Unidentified
Fabricated Case Law (2)
Striking of Counsel’s Appearance + Referral to Bar Authorities + Client Notification Order

AI Use

Counsel filed opposition briefs citing two nonexistent cases. The court suspected generative AI use based on "hallucination" patterns but Counsel neither admitted nor explained the citations satisfactorily. Failure to comply with a standing AI order aggravated sanctions.

Hallucination Details

Two fake cases cited. Citation numbers and Westlaw references pointed to irrelevant or unrelated cases. No affidavit or real case documents were produced when ordered.

Ruling/Sanction

Counsel's appearance was struck with prejudice. The Court ordered notification to the State Bar of Pennsylvania and the Eastern District Bar. Consel was required to inform his client, Bevins, of the sanctions and the need for new counsel if re-filing.

Bischoff v. South Carolina Department of Education Admin Law Court, S.C. (USA) 10 April 2025 Pro Se Litigant Implied Fake citations Warning

The court held that: "It is likely that Appellant employed argument generated by an artificial intelligence (AI) program which contained the fictitious case citation and cautions Appellant that many harms flow from the use of non-existent case citations and fake legal authority generated by AI programs, including but not limited to the waste of judicial resources and time and waste of resources and time of the opposing party. Were courts to unknowingly rely upon fictitious citations, citizens and future litigants might question the validity of court decisions and the reputation of judges. If, alternatively, Appellant's use of a fictitious case was not the result of using an AI program, but was instead a conscious act of the Appellant, Appellant's action could be deemed a fraud on the Court. Appellant is hereby expressly warned that submission of fictitious case authorities may subject Appellant to sanctions under the S.C. Frivolous Proceedings Act, S.C. Code Ann. § 15-36-10(Supp. 2024)."

Daniel Jaiyong An v. Archblock, Inc. Delaware Chancery (USA) 3 April 2025 Pro Se Litigant Implied
False Quotes Case Law (2)
Misrepresented Case Law (2)
Motion denied with prejudice; no immediate sanction imposed, but petitioner formally warned and subject to future certification and sanctions

AI Use

The petitioner submitted a motion to compel discovery that contained several fabricated or misleading citations. The court explicitly stated that the motion bore hallmarks of generative AI use and referenced ChatGPT’s known risk of “hallucinations.” Although the petitioner did not admit AI use, the court found the origin clear and required future filings to include a GenAI usage certification.

Hallucination Details

Examples included:

  • Terramar Retail Centers, LLC v. Marion #2-Seaport Trust – cited for discovery principles it did not contain
  • Deutsch v. ZST Digital Networks, Inc. – quoted for a sentence not found in the opinion
  • Production Resources Group, LLC v. NCT Group, Inc. – attributed with a quote that appears nowhere in the case or legal databases

Court verified via Westlaw that some phrases returned only the petitioner’s motion as a result.

Ruling/Sanction

Motion to compel denied with prejudice. No immediate monetary sanction imposed, but petitioner was warned that further submission of fabricated authority may result in sanctions including monetary penalties or dismissal. Future filings must include a certification regarding the use of generative AI.

Key Judicial Reasoning

The Vice Chancellor emphasized that GenAI can benefit courts and litigants, but careless use that results in fictitious legal authorities wastes resources and harms judicial integrity.

Dehghani v. Castro New Mexico DC (USA) 2 April 2025 Lawyer Unidentified
Fabricated Case Law (6)
False Quotes Case Law (1)
Monetary sanction; required CLE on legal ethics and AI; mandatory self-reporting to NM and TX state bars; report of subcontractor to NY state bar; required notification to LAWCLERK 1500 USD

AI Use

Counsel hired a freelance attorney through LAWCLERK to prepare a filing. He made minimal edits and admitted not verifying any of the case law before signing. The filing included multiple fabricated cases and misquoted others. The court concluded these were AI hallucinations, likely produced by ChatGPT or similar.

Hallucination Details

Examples of non-existent cases cited include:

Moncada v. Ruiz, Vega-Mendoza v. Homeland Security, Morales v. ICE Field Office Director, Meza v. United States Attorney General, Hernandez v. Sessions, and Ramirez v. DHS.

All were either entirely fictitious or misquoted real decisions.

Ruling/Sanction

The Court sanctioned Counsel by:

  • Ordering a $1,500 fine
  • Requiring a 1-hour CLE on AI/legal ethics
  • Ordering him to self-report to the New Mexico and Texas bars
  • Ordering him to report the freelance lawyer to the New York bar
  • Requiring notification of LAWCLERK
  • Requiring proof of compliance by May 15, 2025

Key Judicial Reasoning

The court emphasized that counsel’s failure to verify cited cases, coupled with blind reliance on subcontracted work, constituted a violation of Rule 11(b)(2). The court analogized to other AI-sanctions cases. While the fine was modest, the court imposed significant procedural obligations to ensure deterrence.

D'Angelo v. Vaught Illinois (USA) 2 April 2025 Lawyer Archie (Smokeball) Fabricated citation Monetary sanction 2000 USD
Boggess v. Chamness E.D. Texas (USA) 1 April 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Argument ignored
Source: Jesse Schaefer
Sanders v. United States Fed. claims court (USA) 31 March 2025 Pro Se Litigant Implied
Fabricated Case Law (4)
Misrepresented Case Law (1), Legal Norm (1)
Warning

AI Use

The plaintiff did not admit to using AI, but the court inferred likely use due to the submission of fabricated citations matching the structure and behavior typical of generative AI hallucinations. The decision referenced public concerns about AI misuse and cited specific examples of federal cases where similar misconduct occurred.

Hallucination Details

Plaintiff cited:

  • Tucker v. United States, 24 Cl. Ct. 536 (1991) – does not exist
  • Fargo v. United States, 184 F.3d 1096 (Fed. Cir. 1999) – fabricated citation pointing to an unrelated Ninth Circuit case
  • Bristol Bay Native Corporation v. United States, 87 Fed. Cl. 122 (2009) – fictional
  • Quantum Construction, Inc. v. United States, 54 Fed. Cl. 432 (2002) – nonexistent
  • Hunt Building Co., LLC v. United States, 61 Fed. Cl. 243 (2004) – real case misused; contains no mention of unjust enrichment

Ruling/Sanction

The court granted the government’s motion to dismiss for lack of subject matter jurisdiction under Rule 12(b)(1). Although the court found a clear Rule 11 violation, it opted not to sanction the plaintiff, citing the evolving context of AI use and the absence of bad faith. A formal warning was issued, with notice that future hallucinated filings may trigger sanctions.

Key Judicial Reasoning

Judge Roumel noted that plaintiff’s attempt to rely on fictional case law was a misuse of judicial resources and a disservice to her own advocacy. The court cited multiple precedents addressing hallucinated citations and AI misuse, stating clearly that while leeway is granted to pro se litigants, the line is crossed when filings rely on fictitious law.