The 3rd Circuit Court of Appeals yesterday (29 September) upheld a ruling for Thomson Reuters in its copyright dispute with former legal-research rival Ross Intelligence over Ross’ alleged misuse of copyrighted material to train an AI-powered legal ‌search engine, according to TR’s parent company Reuters.

A report from Reuters states that the court rejected Ross’ argument that its search engine made fair use of material from Thomson Reuters’ Westlaw platform, in what Reuters describes as “a first-of-its-kind ruling by a US appeals court in a wave of high-stakes copyright cases over AI training.” For now we are unable to test that out: we know the outcome but the order is sealed, so we can’t yet see precisely how the Third Circuit framed its reasoning, including what it said about transformative use, market harm and the implications for AI training.

Thomson Reuters’ 2020 lawsuit accused legal research company Ross Intelligence of copying Westlaw’s ‘headnotes,’ which summarize points of law in court opinions. It accused Ross of misusing thousands of headnotes to train its competing AI-based legal search engine.

Ross shut down its platform, opens new tab in 2021, citing the costs of Thomson Reuters’ litigation.

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