1 Dec 2025CzechiaUnidentified legal research tool
On 1 December 2025 the presiding judge of a chamber of the Czech Constitutional Court fined a Prague lawyer 25,000 crowns (a quarter of the statutory maximum) for grossly obstructing proceedings. The lawyer had filed a constitutional complaint, for a client refused a temporary residence permit, that argued from 12 decisions of the Constitutional Court and the European Court of Human Rights; the court found that a substantial part of them did not exist and part were grossly misinterpreted. The order says the complaint showed signs of generative AI and that the court presumed the lawyer had generated it with an AI model and then failed to verify the citations. The lawyer confirmed to INFO.CZ that an AI tool was used, described it as a paid professional model from a legal information system provider, said the output was not checked enough, and expressed regret. The court invited the client to correct the complaint so that the client would suffer no procedural harm; the complaint was later rejected as manifestly unfounded on 30 January 2026. INFO.CZ reported on 10 December 2025 that the lawyer had apologised and paid the fine and that the Czech Bar Association's supervisory board was examining the case.
Core + contextual relations Low reported severity Regulatory Action
AI involvement supported · Causal attribution established · 5 sources · Added 26/10/2026
Dec 2023 to Mar 2024United StatesGrammarly (reported)
In late 2023 a junior at a public high school in Hingham, Massachusetts, and a classmate submitted a script for an AP U.S. History project that, a federal court later found on a preliminary record, contained text copied from Grammarly, a publicly available AI tool, including citations to nonexistent books, with no acknowledgement of AI use. Turnitin and other AI detection tools had flagged the script, and a school official says the pupil admitted using Grammarly. In December 2023 the school treated it as cheating: the pupil failed two parts of the project, served a Saturday detention and was rejected from the National Honor Society in spring 2024, though he was later admitted. His parents sued, arguing the school had not made its AI rules clear; on 20 November 2024 the US District Court for the District of Massachusetts refused a preliminary injunction to undo the penalties, and in February 2025 the parties dismissed the case with prejudice.
Core + contextual relations Low reported severity Involving minors Lawsuit Dismissed
AI involvement reported · Causal attribution supported · 2 sources · Added 23/10/2026
Event date unknownRussiaUnidentified legal research tool
Russia's Court for Intellectual Property Rights fined an individual entrepreneur from Udmurtia 5,000 roubles for contempt of court after finding that part of the 12 references to case law in his cassation appeal, including one said to be a Supreme Court position, pointed to court acts that do not exist or attributed conclusions to them, the court's press service told RIA Novosti on 27 August 2026. Rossiyskaya Gazeta reports that the entrepreneur explained he had prepared the appeal with an AI-based service that selected the case law, and that his side argued he had no legal education and could not check the references; the court rejected the argument that the errors were technical. The date of the ruling and the AI service are not reported.
Core + contextual relations Low reported severity Regulatory Action
AI involvement reported · Causal attribution supported · 2 sources · Added 23/10/2026
15 Jul 2026United StatesUnidentified AI drafting tool
In a published opinion of July 2026, the Arizona Court of Appeals found that a self-represented appellant's opening brief in a probate dispute contained eight citations, six of them deficient, including two cases that do not exist. In a written explanation and at a hearing on the false citations he acknowledged relying on generative AI to write the brief and said he did nothing to verify the citations. The court struck the inaccurate and false citations, rejected the appeal because no supportive authority remained, held that citing a hallucinated case is sanctionable whether or not it is intended, and ordered him to pay the share of the other party's attorney's fees traceable to the fake citations. Because he said he did not intend to deceive and is not legally trained, the court chose this narrow sanction over contempt or fines. It described the opinion as the first published Arizona ruling on generative AI hallucinations in filings.
Core + contextual relations Low reported severity Regulatory Action
AI involvement supported · Causal attribution established · 1 source · Added 18/10/2026
31 Mar 2026 to 11 Sept 2026United StatesIrys (reported)
A Los Angeles County Superior Court judge ordered a senior associate at Musick, Peeler & Garrett, the outside firm defending State Farm in a homeowner's lawsuit over a fire-damaged home, to pay a $999.99 sanction after the associate's motions in limine cited cases, quotations and holdings that did not exist, Law360 reported on 14 September 2026. In a declaration reproduced by Reason's Volokh Conspiracy, the associate said she used an AI program called Irys to prepare the motions, did not check some of the citations, and wrongly believed the program was cite-checked through the firm's Westlaw subscription; she confirmed seven non-existent case citations across eight motions. The plaintiff's lawyers found the citations and raised them at a status conference on 7 August 2026. The firm acknowledged citations that appeared to be AI hallucinations, and its lead trial counsel apologised to the court and the plaintiff. According to Law360, the judge had considered up to $5,000, and the amount set is one cent below the level at which California law requires a court to notify the State Bar.
Core concern Low reported severity Regulatory Action
AI involvement supported · Causal attribution supported · 4 sources · Added 17/10/2026
21 Nov 2025United StatesUnidentified AI drafting tool
On 25 September 2026 a judge of the U.S. District Court for the District of Massachusetts granted a defence motion for sanctions under Federal Rule of Civil Procedure 11 against a California-barred lawyer admitted for one case (pro hac vice) to represent the plaintiff. The court found that an opposition the lawyer filed on 21 November 2025 was replete with inaccurate citations, including a quotation attributed to a case with a fictitious Westlaw citation, and that later oppositions cited a non-existent case. In response to the court's order to show cause, the lawyer admitted using AI to draft the first opposition and explained a belief that the enterprise-level AI software in use did not hallucinate cases. The court revoked the lawyer's pro hac vice admission and ordered the lawyer's firm to pay the defendants' reasonable fees and costs, capped at $10,000. The order does not name the AI product.
Core concern Medium reported severity Regulatory Action
AI involvement supported · Causal attribution supported · 1 source · Added 16/10/2026
2026SpainUnidentified AI drafting tool
The Criminal Chamber of the High Court of Justice of the Canary Islands (TSJC) fined a lawyer 420 euros for breaching the duty of truthfulness and good faith, after an appeal the lawyer filed contained 48 citations of Supreme Court judgments and a report of the General Council of the Judiciary that did not exist. According to the court's order, as described in its press release of 13 February 2026, the lawyer used a general-purpose AI tool to draft the appeal and did not check a single citation against the free public case-law database; the court's documentalist verified that the references were false. The court referred the matter to the lawyer's bar association for possible disciplinary action and set the fine at about half the annual cost of a legal-specific AI tool, taking into account that the lawyer admitted the facts and expressed remorse. The court had first flagged the citations in its judgment dismissing the appeal, reported on 5 January 2026, which opened a separate proceeding. The lawyer told the court of comments and mockery from colleagues after the case became public.
Core concern Low reported severity Regulatory Action
AI involvement supported · Causal attribution established · 3 sources, 2 underlying accounts · Added 16/10/2026
5 Feb 2026 to 9 Oct 2026United StatesvLex, Paxton AI and NotebookLM (reported)
In a federal trademark suit in the U.S. District Court for the Southern District of New York, the court on 5 February 2026 struck a company defendant's motion papers and entered default judgment against it as a sanction on its lawyer, after his filings repeatedly cited nonexistent cases and misattributed quotations. The lawyer said he had found and cite-checked cases with AI tools (vLex and Paxton AI) and used NotebookLM to review a later submission; the court rejected his explanations and found he acted in bad faith. On 9 October 2026 the court described the citations as produced by generative AI and ordered the lawyer to pay $38,877.59 in fees and costs to the firm of a co-defendant's former lawyer, who had reported the false citations to the court.
Core + contextual relations Medium reported severity
AI involvement supported · Causal attribution established · 2 sources, 1 underlying account · Added 16/10/2026
31 Jan 2025 to 12 Dec 2025United StatesUnidentified AI drafting tool
On 12 December 2025 the U.S. District Court for the District of Oregon dismissed with prejudice the claims of plaintiffs in a family dispute over their late mother's estate and family property, as a sanction for what the court called their misuse of generative artificial intelligence, and found their continual violations of the court's Local Rules an additional basis for the dismissal. Three of the plaintiffs' summary-judgment briefs cited fifteen nonexistent cases and fabricated quotations attributed to eight real authorities. The plaintiffs had said the inaccurate citations came from reliance on an automated legal citation tool. The court found that the plaintiffs shared responsibility with their lead lawyer and that one plaintiff, a frequent self-represented litigant, was likely the person who used AI to draft the briefs. It struck the briefs, ordered the lead lawyer to pay $15,500 to the court and awarded the defendants their fees. In March 2026 it set those fees at $94,704.38, ordering the lead lawyer to pay 85% and local counsel 15%. In June 2026 it denied the plaintiffs' motion to reconsider a later ruling for the defendants on a counterclaim.
Core + contextual relations Medium reported severity Lawsuit Dismissed
AI involvement supported · Causal attribution established · 3 sources, 1 underlying account · Added 15/10/2026
24 Apr 2026United StatesUnidentified AI research tool
On 24 April 2026 the Supreme Court of Alabama dismissed an appeal by two siblings in a family dispute over living trusts because their lawyer, W. Perry Hall, had filed briefs in which most of the legal authorities were misquoted or did not exist. The court said they appeared to be AI hallucinations, and at a show-cause hearing in February 2026 Hall admitted that many authorities did not exist and that he had improperly used AI to obtain them. The court ordered Hall to pay the opposing party's fees and costs of $17,200 and double appeal costs, barred him from filing in the court without a co-signing attorney and referred him to the Alabama State Bar. It said the dismissal was imposed as a sanction because of the particularly egregious facts. One justice, concurring in part and dissenting in part, objected to dismissing the appeal as a sanction for the lawyer's conduct but would have affirmed the judgment against the clients on the merits.
Core + contextual relations Medium reported severity Regulatory Action
AI involvement supported · Causal attribution established · 1 source · Added 14/10/2026
Event date unknownEstoniaUnidentified AI writing tool
According to Delfi Ärileht and ERR (both 26 June 2026), complainants who went to the Tallinn Administrative Court to contest a felling permit sent the court a document that cited scientific work on the effects of clear-cutting. The court found that the Estonian scientists named in the references do not exist and that the studies could not be found. It asked how the document had been produced, gave the complainants the chance to submit the cited works, and warned of a fine for attempting to mislead the court. The complainants replied that using AI is not forbidden and that they had not meant to mislead the court. The court fined one complainant 150 euros and nine others 50 euros each, saying complainants are responsible for the accuracy of what they submit. Delfi Ärileht reports that the Tallinn Circuit Court agreed and that the Supreme Court declined the case that week, so the fines are in force. No report names the tool or says which complainant used it.
Core concern Low reported severity Regulatory Action
AI involvement reported · Causal attribution alleged · 2 sources, 1 underlying account · Added 05/10/2026