by Dennis Crouch

The Third Circuit has affirmed partial summary judgment that ROSS Intelligence infringed Thomson Reuters's copyrights when it used Westlaw headnotes to train a competing AI legal search tool. Thomson Reuters Enterprise Centre GmbH v. ROSS Intelligence Inc., No. 25-2153 (3d Cir. Sept. 29, 2026).

Judge Bibas held as a matter of law that ROSS infringed 2,243 headnotes and that the copying was not fair use. He then certified two questions for immediate appeal: whether the headnotes are original, and whether ROSS's use was fair. The Third Circuit answered both for Thomson Reuters in an opinion by Judge Montgomery-Reeves. What remains for trial in Delaware is whether some of those copyrights have expired, the claims on the remaining headnotes, and damages. I previously wrote about Judge Bibas's decision (Feb. 11, 2025) and ROSS's opening brief on appeal (Sept. 23, 2025).

ROSS never showed a headnote to its users. The headnotes were copied and used to write AI training memos, and the finished tool returned only passages from judicial opinions. ROSS argued that this sort of intermediate copying is fair use under cases like Google LLC v. Oracle America, Inc., 593 U.S. 1 (2021). The court disagreed. In its reading, those cases turn on necessity, and ROSS already had the opinions and copied the headnotes because that was easier. "Unlike necessity, ease is not a justification for copying." The court called the dispute "no more than an ordinary copyright case" and set generative AI aside in a footnote responding to the Trump Administration's recent statement of interest in the OpenAI litigation.