The Pulse
Third Circuit Affirms Thomson Reuters’ Win Against Ross Intelligence
The Third Circuit held that Westlaw headnotes are copyrightable and that Ross Intelligence’s use of them to train an AI legal-search tool was not fair use, affirming Thomson Reuters’ win in what Reuters called a first-of-its-kind U.S. appel
AI.info Team · Written with AI ·
A federal appeals court on Tuesday upheld Thomson Reuters’ copyright win over Ross Intelligence, holding that Westlaw headnotes are protected by copyright and that Ross’s use of them to train an AI legal-search engine was not fair use. The U.S. Court of Appeals for the Third Circuit filed its opinion under seal on Tuesday and released it publicly on Wednesday. Reuters and copyright commentators described it as the first ruling by a U.S. appeals court on fair use in AI training.
The panel of Circuit Judges L. Felipe Restrepo, Tamika Montgomery-Reeves and Emil Bove affirmed the Delaware district court’s partial summary judgment for Thomson Reuters. Judge Montgomery-Reeves wrote the opinion of the court; the published opinion contains no dissent. Thomson Reuters is the parent company of Reuters News.
“No more than an ordinary copyright case”
Ross had framed the appeal as a case about the future of AI legal technology. The court rejected that framing at the outset. Montgomery-Reeves wrote:
“In truth, this is no more than an ordinary copyright case; we must determine whether Thomson Reuters’s materials are sufficiently original for copyright protection and whether ROSS’s use of those materials was fair.”
Circuit Judge Tamika Montgomery-Reeves, for the Third Circuit panel
On originality, the court held that all 2,243 headnotes at issue show the required “creative spark,” because Westlaw’s editors decide which points of law to include and how to word them so that each headnote stands on its own. Headnotes are not law, the court said; judicial opinions are, and they remain free for anyone to publish.
Three of four fair-use factors went against Ross
Ross hired LegalEase Solutions to write about 25,000 training memos, and the memo writers used Westlaw headnotes to frame the legal questions. The court found that Ross used the headnotes for the same purpose as Westlaw, helping users find relevant court opinions, in a commercial product priced to compete with Westlaw. Training an AI program “arguably presents a slight degree of difference in use,” the court said, leaving the use “minimally transformative, at best.”
The panel distinguished the computer-code cases Ross relied on, including Google v. Oracle, because copying there was needed to reach unprotected functional elements. Ross had the underlying opinions and could have used them; it used headnotes because they were easy. “Unlike necessity, ease is not a justification for copying,” the court wrote. The nature of the headnotes, which are largely factual, weighed slightly toward fair use, but the amount copied and the market effect weighed against it.
On market harm, the court found that the market for licensing headnotes as AI training data “is rapidly developing” and that Ross usurped Thomson Reuters’ chance to enter it. It also rejected Ross’s arguments that the ruling would halt AI development and that AI’s importance to national security should limit copyright here, finding no evidence for either.
Generative AI cases set apart
In a footnote, the court separated this case from generative AI disputes. It noted the Justice Department’s September 1 statement of interest in the OpenAI copyright litigation in New York, which relied on the 2025 Bartz v. Anthropic ruling to argue that training a large language model is transformative. Unlike those models, the court wrote, Ross’s platform “cannot generate original expression,” and Ross trained its AI to build a commercial substitute for Westlaw.
The appeal came to the Third Circuit after U.S. Circuit Judge Stephanos Bibas, sitting by designation in the district court, ruled against Ross’s fair-use defense in February 2025 and then certified two questions for interlocutory appeal. In his May 2025 opinion explaining that decision, Bibas wrote: “Though I am still confident in my February 2025 summary judgment opinion, there are difficult legal questions about copyright and non-generative AI tools at the heart of this case.”
Responses and next steps
According to Reuters, a Thomson Reuters spokesperson said the company was pleased with the ruling and “firmly believes that respecting copyright is essential for fostering innovation while protecting the intellectual property that fuels fiduciary-grade AI solutions.” Spokespeople and an attorney for Ross did not immediately respond to Reuters’ requests for comment. Ross shut down its platform in 2021, citing the cost of the litigation.
When it filed the opinion on Tuesday, the court ordered the parties to propose any redactions within 10 days. The version published on Wednesday carries no redactions. Bibas had stayed the district-court case while the appeal was pending.