ROSS Intelligence asks full Third Circuit to rehear Thomson Reuters AI-training copyright ruling

What happened

On 4 November 2026, ROSS Intelligence asked the full U.S. Court of Appeals for the Third Circuit to rehear its copyright case against Thomson Reuters, seeking a new appellate hearing after a three-judge panel ruled against it in September. The petition asks the full court to revisit the panel's conclusion that ROSS infringed copyright by training its AI legal-research service on material from Thomson Reuters' Westlaw.

Background

Thomson Reuters sued ROSS in 2020 in the District of Delaware (No. 1:20-cv-00613), alleging ROSS built its competing legal-research tool using thousands of question-and-answer "bulk memos" derived from Westlaw headnotes, obtained through a third party after Thomson Reuters declined to license the content. In February 2025 the district court granted partial summary judgment for Thomson Reuters, holding 2,243 Westlaw headnotes original and infringed and the use not fair use. On 29 September 2026 a Third Circuit panel (Judges Restrepo, Montgomery-Reeves and Bove) affirmed, holding the headnotes copyrightable and ROSS's training use not fair use. It was the first U.S. appellate ruling on fair use in AI training, though the opinion noted ROSS's tool was not generative AI and returned existing passages rather than creating new text.

What this does and does not change

Nothing is decided yet. A petition for rehearing en banc asks the full court to reconsider the panel's ruling; the court has not ruled on the petition. The panel decision stands unless the full court agrees to rehear the case or a higher court intervenes.