Overview
- A three‑judge panel of the 3rd U.S. Circuit Court of Appeals affirmed the lower court’s finding that Westlaw headnotes are protectable copyright and that ROSS’s use of them to build its legal search product was not fair use.
- Westlaw headnotes are editorial summaries added to public judicial opinions and the court said those added summaries can receive copyright protection even though the underlying opinions are in the public domain.
- The dispute involved a non‑generative legal search system that copied headnotes before the rise of mainstream large‑language models, and the court stressed ROSS used the material to compete directly with Thomson Reuters.
- The written opinion is currently sealed while parties may request redactions, and the decision leaves in place the February 2025 summary judgment that prompted this interlocutory appeal.
- Practically, the ruling strengthens publishers’ leverage to demand licenses, prompts corporate legal and procurement teams to verify vendor training data, and could narrow safe‑harbor arguments for commercial AI tools that rely on proprietary editorial content.