AI company argues its use of scraped Westlaw legal data was transformative

(CN) — A defunct artificial intelligence company aimed at aiding legal research told a three-judge Third Circuit panel Thursday that its use of Westlaw data to train its AI was transformative.

Westlaw owner Thomson Reuters sued ROSS Intelligence in 2020, claiming the AI company used a third party called LegalEase Solutions to get access to the legal research platform’s headnotes — short descriptions of important issues of law that appear before judicial opinions — after it was refused access. ROSS did this to “rush out” a competing product without spending the time and resources to create it itself, Reuters said in its complaint.

A lower court found in favor of Reuters in 2025, affirming its argument that ROSS trampled on copyrighted work and denying ROSS’ argument that its actions fell under fair use. ROSS appealed, landing the case before the Third Circuit, where the company said Thursday that not finding in its favor would impede AI progress in the U.S.

“Fair use ruling here brings into question the core technology of the AI revolution,” Mark S. Davies of White & Case in Washington, attorney for ROSS, argued.

“Why is it transformative as opposed to just a different type of legal search engine?” U.S. Circuit Judge Emil Joseph Bove III pressed, as Davies tried to explain how the company’s product was transformational from the user’s perspective.

“What we have taught this machine, now, is how to think like a lawyer. Like you get the question, you go find it,” Davies said. The search product did not employ generative AI that could hallucinate, he clarified, but could answer a legal question the model had never seen before.

“It’s spectacularly transformational,” he added. “And we took so little, we just took — 0.08% is all we copied of 28 million headnotes … This is legal context, it’s not something that is a creative, it’s not poetry, it’s not like the creative works that are going on in the other district court cases.”

ROSS used 25,000 headnotes out of Westlaw’s library of over 28 million headnotes, the company says.

But U.S. Circuit Judge Tamika Montgomery-Reeves, a Joe Biden appointee, asked why Westlaw’s headnotes are not sufficiently original to qualify for copyright.

Judicial opinions are owned by the public and the headnotes lack creativity, Davies said.

“This is a copyright case,” he said. “It’s an interesting case, it raises lots of issues, but it’s a copyright case and the point of copyright is progress.”

“Copyright is not a privilege reserved for the well-behaved,” Davies added.

Dale Cendali of Kirkland & Ellis in New York, representing Reuters, said the Supreme Court has already determined the headnotes are copyrightable material.

“The law draws a distinction between things that are the work of people writing about law and the law itself,” she said.

Reuters argues it suffered market harm because of ROSS’ copying of Westlaw data. ROSS’ product was a substitute to Westlaw and was marketed as such, Cendali said, adding that the company harmed the exclusivity of Reuters’ data to train its own AI product.

“They’re selling the same product, that does the same thing, and there’s nothing transformative about it,” she said.

“They had the cases; their own experts admitted that they could have done their own analysis themselves and come up with questions and question pairs to do the same thing,” Cendali said. “They didn’t need to copy us, they just wanted to.”

Cendali noted Reuters offered WestSearch, a product that used AI-based ranking algorithms, in 2010, four years before ROSS broke onto the scene. She called ROSS a latecomer to the AI legal scene, rather than an innovator. Reuters’ competitor LexisNexis also developed a similar AI product around the same time, she added.

The excuse that using AI would make ROSS’ data scraping fair use is just “wrong fundamentally under the law,” Cendali said.

“It was not necessary to scrape the headnotes to get to the legal opinion, right?” Bove, a Donald Trump appointee, asked Davies.

“We were under huge time pressure,” Davies said. “These startups still don’t have a lot of time, they have to raise money, they have to move fast.”

Bove concluded, “I think this case is about balancing what we have and where are the right lines.”

The Westlaw headnotes are not copyrightable, ROSS argues in its brief, nor are they creative or original, and instead reiterate uncopyrightable judicial opinions. The company transformed the headnotes it used, it said, and had “quintessential fair use.”

“Concluding that headnotes are original would effectively give West a monopoly over the law, which, as courts have recognized, belongs to no one,” the company wrote.

ROSS hired LegalEase Solutions to produce a library of AI training data, including questions that were “often adapted from Westlaw headnotes” after it was refused a Westlaw subscription. Westlaw doesn’t give competitors access to its products.

The Westlaw headnotes are original content that ROSS copied, Reuters counters in its brief. The company’s attorney-editors summarize key issues and link to relevant parts of the case, and the headnotes are meant to be understood separate from judicial opinions.

The company already had case law and could have done its own analysis, Reuters said. ROSS took answers to legal questions linked to case law, Reuters said, and that action was not protected by fair use.

ROSS affected Westlaw’s market and value by attempting to create a competing product, the company added, acting for commercial gain and in bad faith.

“ROSS copied the heart of Westlaw, the editorial content that makes it valuable,” Reuters wrote.

Davies told Courthouse News, “The AI industry has grown exponentially since the Third Circuit granted interlocutory review in this case, and continued uncertainty in this area presents significant challenges for creators, developers, and users. A ruling in favor of ROSS will ensure a stable and predictable legal framework as this transformative technology continues to evolve.”

In the lower court, U.S. Circuit Court Judge Stephanos Bibas initially denied both parties’ motions for summary judgment on the questions of copyright and fair use of the headnotes, opting to send those questions to a jury. He later revised his 2023 opinion.

U.S. Circuit Judge L. Felipe Restrepo, a Barack Obama appointee, also served on the panel.

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