3D CIR.Court order
Third Circuit affirms Thomson Reuters win over ROSS on Westlaw headnotes and AI training
Updated : The Third Circuit has since posted its precedential opinion, which was filed on September 29 under temporary seal.
The U.S. Court of Appeals for the Third Circuit on September 29, 2026, affirmed a Delaware federal judgment that ROSS Intelligence infringed Thomson Reuters Westlaw headnotes and could not claim fair use for using them to train a competing AI legal research tool, Bloomberg Law and Copyright Lately reported. The precedential opinion, filed under temporary seal on September 29, is now public on the court's website.
Order (Bloomberg Law) → · Copyright Lately, LawSites, U.S. Court of Appeals for the Third Circuit +1
Read the long piece on LexRegister
Key points
- The Third Circuit affirmed Judge Stephanos Bibas's February 2025 ruling for Thomson Reuters against ROSS.Bloomberg LawCopyright Lately
- The panel rejected ROSS's fair-use defense for using Westlaw headnotes to train a competing AI tool.Bloomberg LawCopyright Lately
- The precedential opinion, by Judge Montgomery-Reeves with Judges Restrepo and Bove, was filed under temporary seal and is now public.U.S. Court of Appeals for the Third Circuit
- Copyright Lately reported the public judgment states the lower court was "AFFIRMED."Copyright Lately
- Outlets described the decision as the first federal appellate ruling on fair use in AI training.Bloomberg LawCopyright Lately
Sources6 articles across 5 outlets
U.S. District Court for the District of Delaware
Bloomberg Law
Copyright Lately
LawSites
U.S. Court of Appeals for the Third Circuit
Filed under
Court orderThomson ReutersROSS IntelligenceU.S.3d Cir.D. Del.Intellectual propertyLitigationTechnologyFor practitionersFor governanceFor vendors