Ross Intelligence trained its AI on Westlaw's headnotes — a court called it theft

Ross Intelligence built a competing AI legal-research tool and wanted to train it on Westlaw's headnotes — Thomson Reuters' editorial summaries of case law. Thomson Reuters refused to license them, so Ross paid a third-party vendor, LegalEase, to produce 'Bulk Memos' built directly from Westlaw's headnotes and Key Number System.

Thomson Reuters sued for copyright infringement in 2020. On February 11, 2025, Judge Stephanos Bibas of the District of Delaware ruled against Ross on summary judgment, finding the headnotes copyrightable and Ross's use not fair use — the copying wasn't transformative, and it created a competing product in Thomson Reuters' own potential AI-training-data market.

The ruling was the first major US decision on fair use in AI training, and it went the copyright holder's way on every factor the court weighed. Ross had already shut down years earlier, unable to keep funding the defense — the case survived its own defendant.