The 3rd U.S. Circuit Court of Appeals recently ruled in favor of Thomson Reuters in its longstanding copyright battle with ROSS Intelligence, a now-defunct AI legal research company. This decision focused on two key legal issues: the copyrightability of Westlaw headnotes and the application of fair use in the context of artificial intelligence training, marking the first federal appellate decision to address the latter.
Although the full opinion remains under seal pending potential redaction requests, the appellate court’s panel affirmed the lower court’s summary judgment in favor of Thomson Reuters, originally issued by Judge Stephanos Bibas in February 2025. The ruling confirmed that the Westlaw headnotes are sufficiently original to warrant copyright protection. Furthermore, the court concluded that ROSS’s use of these headnotes as training data did not qualify as fair use.
Despite the significance of the ruling to the parties involved, its broader implications remain uncertain. Some experts suggest that the case could affect ongoing litigation involving tech giants like OpenAI, Anthropic, and Meta regarding their use of copyrighted materials for training AI models. However, the specific circumstances of the ROSS case—predicated on actions taken before the onset of generative AI and involving a non-generative AI system—may limit its impact.
The crux of the case was ROSS’s use of Thomson Reuters-derived materials to construct a legal research tool meant to compete directly with Westlaw. The ruling follows an interlocutory appeal from a summary judgment order, and a Thomson Reuters spokesperson expressed satisfaction with the outcome, emphasizing the necessity of copyright respect to spur innovation while safeguarding intellectual property that powers advanced AI solutions.
- The lower court had ruled that short quotes or paraphrases of judicial holdings could be copyrightable.
- It had also been determined that ROSS’s internal use of Westlaw headnotes did not fall under fair use protections.
As the full opinion becomes available, legal practitioners keen to understand its full implications will be better able to assess its impact on related technological and legal landscapes. Whether the opinion will serve as a precedent or be interpreted narrowly based on its specific facts remains to be seen.