Thomson Reuters v. Ross Intelligence — First U.S. AI-Training Fair-Use Ruling (D. Del.)

Thomson Reuters sued legal-research startup Ross Intelligence in 2020 for copying Westlaw headnotes to train a competing AI legal-research tool. In February 2025, Judge Stephanos Bibas (sitting by designation) granted summary judgment to Thomson Reuters on direct copyright infringement and rejected Ross's fair-use defense — the first definitive U.S. ruling on AI-training fair use. No jury trial occurred: a 2023 opinion had denied summary judgment and pointed toward trial, but the court invited renewed briefing and reversed course in the 2025 ruling.

Technical detail

Thomson Reuters Enterprise Centre GmbH v. Ross Intelligence, Inc., No. 1:20-cv-00613 (D. Del., filed May 6, 2020; Judge Stephanos Bibas, sitting by designation from 3d Cir.). Feb. 11, 2025: Memorandum Opinion granting partial summary judgment to plaintiff: (1) 2,243 Westlaw headnotes infringed; (2) fair use rejected on all four factors, with factor 4 (market effect) decisive because Ross built a competing legal-research product. Case is on appeal to 3d Cir. as of 2026 — likely the first federal appellate ruling on generative-AI training fair use.

Who is protected: Copyright holders in legal-research and similar databases vis-à-vis competitive AI products

Who must comply: Ross Intelligence, Inc. and similarly situated AI competitors training on a rival's copyrighted database

Key facts

More AI rules in D. Del.

• Getty Images v. Stability AI (US) · Blocked / in litigation

Related copyright and training data rules elsewhere

• Hachette v. Google (Gemini AI copyright) · Blocked / in litigation
• Copyright Office AI Guidance · In effect
• USPTO AI Inventorship Guidance · Repealed / replaced
• NYT v. OpenAI / Microsoft · Blocked / in litigation
• Authors Guild v. OpenAI · Blocked / in litigation
• Tremblay v. OpenAI · Blocked / in litigation