A US judge has ruled that now-defunct legal research firm Ross Intelligence cannot use Thomson Reuters content to develop an AI-based legal platform.

This marks the first fair use decision in an AI-related copyright case.

Fair use allows limited use of copyrighted works, a defense often cited by tech firms like OpenAI, Microsoft, and Meta in AI training disputes.

While they argue this qualifies as fair use, copyright holders claim it creates competing products and harms their businesses.

Thomson Reuters, the owner of Westlaw and Reuters News, supported the ruling, emphasizing that Westlaw’s attorney-curated content is copyrighted and Ross’s use did not meet fair use criteria.