US Appeals Court Upholds Thomson Reuters Win in AI Training Case

The 3rd US Circuit Court of Appeals upheld a copyright ruling for Thomson Reuters in its case against Ross Intelligence, according to Reuters. The court rejected Ross Intelligence's claim that using material from the Westlaw legal research platform to train an AI powered search engine qualified as fair use.

The decision affirms a 2025 Delaware federal court ruling that Ross Intelligence's use was not transformative because it helped create a competing legal research product. Thomson Reuters accused the company of copying thousands of Westlaw headnotes, which summarize legal points from court opinions.

The ruling is the first by a US appeals court in a copyright dispute over AI training. The case does not involve generative AI. The appeals court's reasoning remains sealed, and Ross Intelligence closed its platform in 2021 after citing litigation costs.