IP Law Daily, PATENT—D. Kan.: Unverified AI-generated citations result in sanctions for licensing entity’s legal team, (Feb 4, 2026)

By Ravindra Kumar Singh, B.L.

The attorneys used AI-generated case citations, invented quotations, and mischaracterized holdings as legal authority without verification.

A federal district court in Kansas has sanctioned five attorneys representing a patent-assertion entity after finding that they violated Rule 11 of the Federal Rules of Civil Procedure by filing briefs riddled with fabricated case citations, nonexistent quotations, and misstatements of binding precedent generated through unverified use of generative artificial intelligence (AI). The court imposed monetary sanctions ranging from $1,000 to $5,000, revoked the pro hac vice admission of one out-of-state attorney, and struck down portions of the plaintiff’s briefing (Lexos Media IP, LLC v. Overstock.com, Inc., No. 2:22-cv-02324-JAR (D. Kan. Feb. 2, 2026)).

Background. The sanctions arose in a patent infringement action filed by Lexos Media IP, LLC, a non-practicing entity that asserted the same website-interface patents against multiple defendants nationwide, including Overstock.com, Inc. Lexos alleged that Overstock infringed three patents relating to modifying the appearance of a computer cursor on a website in response to user interaction.

Overstock moved for summary judgment and separately sought to exclude Lexos’s technical and damages experts under Daubert. On June 13, 2025, Overstock filed its motions, and Lexos timely filed oppositions on July 7, 2025, signed by five attorneys—three Texas-based pro hac vice counsel, a Kansas local counsel, and an associate attorney.

After reviewing Lexos’s opposition to Overstock’s motion to exclude its technical expert, Overstock identified numerous defects in the cited authority. The brief relied on purported Federal Circuit and Tenth Circuit precedent for the proposition that an expert’s use of an incomplete claim construction went to weight rather than admissibility. Overstock demonstrated that many of the cited cases were nonexistent, misquoted, or stood for propositions directly contrary to those asserted.

Eight days later, Lexos sought leave to file a corrected brief, admitting that certain citations and quotations “could not be substantiated” and acknowledged that generative AI had been used in drafting. The court denied Lexos’s request to substantively rehabilitate the brief, struck the offending authority, and sua sponte issued an order to show cause why sanctions should not be imposed.

Court’s opinion. The court’s analysis centered on Federal Rule of Civil Procedure 11(b), which requires attorneys to certify that legal contentions are warranted by existing law or by a nonfrivolous argument for its extension. Applying an objective reasonableness standard, the court held that citing nonexistent authority, fabricating quotations, and misrepresenting precedent plainly violated Rule 11.

The court emphasized that Rule 11 duties are nondelegable. Quoting Business Guides, Inc. v. Chromatic Communications Enterprises, Inc., 498 U.S. 533, 551 (1991), the court reiterated that by signing a filing, an attorney certifies that they conducted a reasonable inquiry into both the facts and the law. The court further relied on Cooter & Gell v. Hartmarx Corp., 496 U.S. 384, 393 (1990), underscoring that Rule 11 exists to deter baseless filings and protect judicial resources.

The court rejected any suggestion that the use of AI itself was sanctionable. Citing Moore v. City of Del City, No. 25-6002, 2025 WL 3471341 (10th Cir. Dec. 3, 2025), the court acknowledged that there is “nothing inherently problematic” about attorneys using generative AI. The violation, however, arose from the complete failure to verify AI-generated output before submitting it to the court.

Fabricated authority and misstatements of law. The court catalogued eleven categories of defective citations in Lexos’s filings. These included nonexistent district court opinions, fabricated quotations attributed to Federal Circuit decisions, incorrect citations to cases that addressed unrelated issues, and mischaracterizations of holdings that directly contradicted Lexos’s asserted propositions.

Citing Mata v. Avianca, Inc., 678 F. Supp. 3d 445, 461 (S.D.N.Y. 2023), the court reiterated that “a fake opinion is not ‘existing law’ and citation to a fake opinion does not provide a non-frivolous ground for extending, modifying, or reversing existing law.” The court also noted that several of the misstatements went to the core legal issue presented by Overstock’s Daubert motion and were not minor or incidental errors.

Responsibility of signing attorneys. The court rejected attempts by senior counsel and local counsel to distance themselves from the defective filings. Relying on Pavelic & LeFlore v. Marvel Entertainment Group, 493 U.S. 120, 126–27 (1989), the court held that every attorney whose name appeared on the signature block bore independent responsibility under Rule 11.

Citing Wadsworth v. Walmart Inc., 348 F.R.D. 489, 495–96 (D. Wyo. 2025), the court emphasized that blind reliance on co-counsel—whether senior, subordinate, or out-of-state—constitutes an improper delegation of Rule 11 obligations. The court found that two senior attorneys had not even read the filings before allowing their names to be affixed, conduct that it described as objectively unreasonable.

Local counsel, who reviewed but failed to cite-check the briefs before filing them through the court’s electronic system, was likewise found to have violated Rule 11. The court stressed that local counsel plays a critical gatekeeping role, particularly where pro hac vice attorneys cannot file directly.

Sanctions. The court imposed the most severe sanctions on the attorney who admitted to using generative AI to generate case law without verification. It fined him $5,000, revoked his pro hac vice admission, ordered him to self-report to state disciplinary authorities, and required him to file a certificate outlining internal procedures designed to ensure citation accuracy. While the court acknowledged the attorney’s personal family hardships, it found that he could have sought an extension or assistance from co-counsel rather than resorting to unverified AI output.

Two senior attorneys who signed the filings without review were each fined $3,000. The court further ordered the managing partner of their firm to implement and certify firm-wide policies addressing AI competence, supervision, and verification, noting that a blanket prohibition on AI use without training or enforcement was insufficient.

The attorney who was local counsel was fined $1,000, with the court crediting his acceptance of responsibility and remedial steps, including the adoption of formal AI policies and his voluntary decision to refrain from sponsoring pro hac vice admissions for one year. The most junior attorney, an associate, received only a public admonishment, with the court citing power imbalances and lack of supervisory authority.

Finally, the court noted that the “sheer amount of case law that has erupted over the last few years due to attorneys’ reliance on unverified generative AI research, often generating hallucinated legal authority, is staggering.”

The Case is No. 2:22-cv-02324-JAR.

Judge: Robinson, J.

Attorneys: Kenneth P. Kula (Buether Joe & Counselors, LLC) for Lexos Media IP, LLC. Aiden Berdahl (Fish & Richardson PC) for Overstock.com, Inc.

Companies: Lexos Media IP, LLC; Overstock.com, Inc.

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