Thomson Reuters has secured a significant court win in an AI copyright lawsuit against Ross Intelligence, a legal AI startup accused of reproducing materials from Westlaw. The ruling gives copyright owners a notable victory at a time when courts are weighing how AI companies may use protected works.
The case matters beyond the two companies because fair use has become a central defense in many AI copyright disputes. In this ruling, US Circuit Court Judge Stephanos Bibas rejected Ross Intelligence’s defenses and found that Thomson Reuters’ copyright was infringed.
What the court decided
Thomson Reuters filed the lawsuit in 2020 against Ross Intelligence. The company argued that Ross Intelligence reproduced materials from Westlaw, its legal research firm, while building a competing legal AI product.
Judge Bibas, sitting by designation in the US District Court of Delaware, ruled in Thomson Reuters’ favor in a summary judgement. His decision was direct: “None of Ross’s possible defenses holds water. I reject them all,” he wrote.
Ross Intelligence did not respond to a request for comment. Thomson Reuters spokesperson Jeffrey McCoy welcomed the outcome in a statement emailed to WIRED. “We are pleased that the court granted summary judgment in our favor and concluded that Westlaw’s editorial content created and maintained by our attorney editors, is protected by copyright and cannot be used without our consent,” he wrote. “The copying of our content was not ‘fair use.’”
Why fair use became the key issue
The ruling focused in part on fair use, a doctrine that can allow copyrighted material to be used without permission in some circumstances. The source article describes examples such as parody works, noncommercial research, and news production.
Courts consider four factors when weighing fair use. Those factors include the reason behind the work, the nature of the copyrighted material, how much of it was used, and the effect on the market value of the original.
In this case, Thomson Reuters prevailed on two of the four factors. Judge Bibas treated the fourth factor as especially important and concluded that Ross “meant to compete with Westlaw by developing a market substitute.”
That point is central for AI companies. Many legal fights over artificial intelligence involve whether training or building AI tools with copyrighted material can qualify as fair use. This decision signals that courts may closely examine whether an AI product is competing with the original source material or replacing demand for it.
The wider AI copyright fight
The generative AI boom has produced many disputes over how copyrighted work can be used in AI systems. The source article notes that major AI tools were developed using copyrighted works including books, films, visual artwork, and websites.
Several dozen lawsuits are currently moving through the US court system. There are also international challenges in China, Canada, the UK, and other countries.
This case is different in one important respect: it is described as the first major AI copyright case in the United States to produce this kind of win for a copyright owner. That does not resolve every pending lawsuit, but it gives other courts, companies, and rights holders a concrete decision to study.
The decision also shows how expensive these fights can become. Ross Intelligence had already shut down in 2021, citing the cost of litigation. By contrast, the source article notes that companies such as OpenAI and Google are better positioned financially to endure long legal battles.
What experts say it could mean
Legal observers quoted in the source article saw the ruling as a setback for AI companies relying on fair use arguments.
Cornell University professor of digital and internet law James Grimmelmann said: “If this decision is followed elsewhere, it's really bad for the generative AI companies.” He also believes the judgement suggests that much of the case law generative AI companies cite for fair use may be “irrelevant.”
Chris Mammen, a partner at Womble Bond Dickinson who focuses on intellectual property law, said the ruling could make fair use arguments harder for AI companies, though the outcome may vary depending on the plaintiff. “It puts a finger on the scale towards holding that fair use doesn’t apply,” he says.
The stakes from here
The Thomson Reuters AI copyright win does not answer every unresolved question about artificial intelligence and protected content. The source article makes clear that many cases are still pending, and different disputes may involve different plaintiffs, facts, and uses of copyrighted material.
Still, the decision puts pressure on one of the most important legal arguments in the AI industry. If other courts follow this reasoning, companies building AI tools may face a tougher path when they claim that using copyrighted works without consent is protected by fair use.
For publishers, database owners, artists, authors, and other rights holders, the ruling may strengthen arguments that editorial work and other protected material cannot be copied into a competing AI product without permission. For AI companies, it is a warning that fair use defenses may not be enough when the court sees a market substitute.