Third Circuit upholds Thomson Reuters’ Westlaw copyright win over Ross Intelligence

Law360 reports that the Third Circuit affirmed a Delaware court’s ruling that Ross Intelligence infringed Westlaw headnotes by using material derived from them to develop an AI-powered legal search tool. Law360 describes it as the first U.S. appellate ruling to address whether AI training can be fair use of copyrighted material. MLex says the accompanying opinion was temporarily filed under seal; the Delaware court had found in February 2025 that copying protected works during algorithmic training was not fair use.