Sony Music and Warner Music have filed a lawsuit against Anthropic, a U.S. artificial intelligence (AI) company, accusing it of illegally using thousands of copyrighted musical works to train its AI models. The lawsuit was filed in a federal court in Northern California and names Anthropic, its CEO Dario Amodei, and co-founder Benjamin Mann as defendants. The music publishers described the alleged violations as "among the most significant and serious cases of intellectual property theft." They claim that Anthropic used "tens of thousands" of copyrighted musical compositions without permission, which makes this case broader in scope than other copyright lawsuits the company is currently facing. According to the 48-page complaint, Anthropic allegedly conducted a large-scale campaign of downloading and scraping copyrighted works to train its AI models, including its series called "Claude." The publishers argue that the company copied these works without authorization and used them to develop its technology. They are seeking damages potentially amounting to several hundred thousand dollars for each work found to be infringed. The case raises complex legal issues, as a single song can contain multiple separately protected elements—such as lyrics, musical composition, and sound recordings—each of which may be owned by different parties, including songwriters, musicians, and record labels. The lawsuit also highlights the potential for high statutory damages, which copyright holders can claim without proving the exact financial loss they suffered. This could significantly increase the financial risk for AI companies accused of infringement. For comparison, a separate lawsuit brought by BMG against Anthropic involves the infringement of 493 musical compositions, which could still expose the company to substantial liability if found responsible. This is not the first time Anthropic has faced legal challenges over the use of copyrighted material. In September 2025, the company settled a $1.5 billion copyright infringement lawsuit with authors and publishers, marking the largest such settlement in U.S. history. However, this new lawsuit from the music industry opens a new front in the ongoing debate about whether AI companies can train their systems using copyrighted works without permission or compensation. Anthropic has denied the allegations and stated it intends to defend itself in court.