Thomson Reuters v. ROSS Intelligence
Whether using Westlaw headnotes to build a competing legal-research AI is fair use.
- Plaintiff
- Thomson Reuters
- Defendant
- ROSS Intelligence
- Type
- Copyright
- Status
- Key ruling — A significant ruling has issued; the case may continue or head to appeal.
- Filed
- May 2020
- Court
- U.S. District Court, D. Delaware
What’s happening
Thomson Reuters sued ROSS Intelligence for using Westlaw editorial content (headnotes) to build a competing legal-research tool. In February 2025 the court ruled the use was not fair use, an early and influential decision against an AI company. Notably, ROSS involved non-generative AI that competed directly with the source product, which shaped the analysis.
Latest: In February 2025 the court ruled there was no fair use — an early, influential decision against an AI company, though it involved non-generative AI competing directly with the source product.
Sources
Verified Jul 11, 2026.
This page is a neutral summary drawn from public reporting, not legal advice — allegations are allegations until a court decides. Litigation moves fast, so the sources above are the source of truth; confirm the latest there. Spotted an error? Tell us — corrections welcome.