Ross Intelligence asks Third Circuit to rehear Westlaw copyright ruling

Ross Intelligence has asked the US Court of Appeals for the Third Circuit to reconsider its ruling on Westlaw headnotes used to develop an AI legal search tool. Its petition in case No. 25-2153 seeks rehearing by the panel or by the full court, known as rehearing en banc. Ross argues that the judges misconstrued three of the four factors used to assess fair use under copyright law.

Ross contests three fair-use factors

The Third Circuit upheld a district court’s findings that 2,243 Westlaw headnotes met copyright’s originality requirement and that Ross’s use was not fair use, according to ArentFox Schiff’s account of the ruling. The firm dates the opinion to 29 September 2026 in its case citation. Wolters Kluwer lists 1 October 2026 in its case-date field.

The headnotes are Westlaw editors’ summaries of points of law in judicial opinions. Ross had obtained training materials based on them from LegalEase, a third party, after Thomson Reuters declined to license its content to Ross. The district court granted Thomson Reuters partial summary judgment but reserved headnotes numbering in the thousands, along with the possible lapse of some copyrights, for later proceedings. AI Affairs reported the appellate decision.

Ross’s petition identifies its first objection as the panel’s focus on the company’s eventual business objective rather than its particular use of the copyrighted material. On the third factor, which concerns how much of a work was used, Ross argues that the panel disregarded the absence of copyrighted material from what it made available to the public. Its fourth-factor objection concerns the markets the panel treated as relevant.

The petition describes Ross’s intended product as a search engine that would respond to a question with passages from judicial opinions. It says the headnotes helped develop questions for training materials that paired sample queries with relevant passages. According to Ross, the trained tool returned quotations from opinions rather than the headnotes themselves. That account is central to its objection about what users could see, but the panel assessed the copying involved in building the tool as well as the tool’s output.

The Third Circuit’s Westlaw market analysis

The panel treated Ross’s purpose as commercial and, in ArentFox Schiff’s account, called the use “minimally transformative, at best”. Both Ross and Thomson Reuters used headnotes to develop legal research platforms. The court also considered Ross’s copying of whole headnotes under the third fair-use factor. Only the second factor, concerning the nature of the copyrighted work, weighed slightly in Ross’s favour.

For the fourth factor, the panel identified effects on the legal research market and on a market it called “rapidly developing” for licensing headnotes as AI training data. Ross’s petition challenges the way the court defined the relevant markets. Its counsel argues that reconsideration is warranted to maintain consistency with decisions of the Third Circuit and the Supreme Court, and says the panel’s decision conflicts with rulings by other federal appeals courts.

That leaves the judges with a request to revisit their application of fair use in this dispute, rather than a request to decide copyright treatment for AI training generally. The petition asks either the same panel or the full court to rehear the case. Ross is represented in the petition by Gibson, Dunn & Crutcher, Pillsbury Winthrop Shaw Pittman and White & Case.

Generative AI remains outside the ruling

The Third Circuit distinguished Ross’s tool from generative AI: the tool at issue did not generate original expression. The court’s ruling therefore left open how fair-use factors apply to training models that create new content. It also did not decide whether headnotes consisting of verbatim quotations from opinions qualify for copyright protection.

Ross’s corporate disclosure, submitted with the rehearing petition under federal and Third Circuit appellate rules, states that the company has no parent corporation, issues no stock and has no publicly held corporation with a financial interest in the proceeding.