CopyrightA US appeals court rejects a fair-use defense for AI training for the first time

The US Court of Appeals for the Third Circuit on September 30 upheld the lower court's ruling in Thomson Reuters' case against ROSS Intelligence. It held that ROSS's use of more than 2,000 Westlaw headnote summaries to train a competing AI legal research tool is not fair use. The lower court reasoned that ROSS took the headnotes to make it easier to build a competing tool, so the use was not transformative. It is the first appellate ruling in the wave of AI-training copyright cases.

The case involves a search tool that finds case law, not generative AI. The appeals court's opinion was first filed under seal and has since been released. Observers say it may inform how courts weigh fair use in other AI-training disputes.