Third Circuit Affirms Copyright and Fair Use Rulings in ROSS Case
LawSites reported on October 12, 2026 that the Third Circuit had unsealed its opinion in Thomson Reuters v. ROSS Intelligence, No. 25-2153. The court's opinion is dated September 29. On an interlocutory appeal, it affirmed partial summary judgment involving 2,243 Westlaw headnotes, holding that the headnotes contained copyrightable expression and that ROSS's copying to train a competing legal search tool was not fair use. The first, third and fourth fair use factors weighed against ROSS; the second favored fair use. The court emphasized that ROSS returned passages from existing judicial opinions rather than generating new expression, and distinguished generative AI cases. It did not decide the originality of the West Key Number System, an issue ROSS had forfeited.
PARADIGM INSIGHTS:
The opinion ties fair use to the purpose of the copying, the protected expression and competition with the original service. It does not make every use of structured legal material to train AI infringing, establish a universal divide between retrieval and generation, or decide whether a different generative model's training is fair use.
Sources
Sign up for Paradigm alerts.
Join the Paradigm Insights list for future case alerts and selected firm updates.