Sony Music Publishing and Warner Chappell Music have jointly filed a monumental copyright infringement lawsuit against Anthropic and its founders, Chief Executive Officer Dario Amodei and Benjamin Mann. Filed late Friday, August 28, in the US District Court for the Northern District of California, the 48-page complaint accuses the AI startup of committing "one of the largest and most blatant ongoing thefts of intellectual property in history."

The case is being viewed as the opening salvo in what could become a yearslong legal battle over the use of music in artificial intelligence systems. It will also likely test how intellectual property is protected in a rapidly developing technological era.

The Multi-Billion Dollar Stakes

The legal action seeks a jury trial and severe financial penalties. The plaintiffs are demanding statutory damages of up to $150,000 for each infringed work, alongside an additional $25,000 for every instance where Anthropic allegedly removed copyright management information. If successful, this could result in billions of dollars in damages.

With this latest filing, the publishing arms of all three major music companies are currently engaged in active litigation against the Claude maker. Universal Music Publishing Group, Concord Music Group, and ABKCO previously filed a suit in Nashville in October 2023 over roughly 500 songs, which was later transferred to California.

Those same publishers then filed a second suit in January 2026, seeking more than $3 billion in damages over the unauthorized use of more than 20,000 copyrighted songs for AI training purposes. Further escalating the legal pressure, BMG brought a third case in March 2026 over 493 compositions. Most recently, Round Hill Music filed a fourth copyright lawsuit against the company on August 17.

A Pattern of Legal Battles

In September 2025, Anthropic ultimately settled the authors' lawsuit for a record-setting $1.5 billion. However, the music publishers argue that this penalty is completely insufficient to deter future infringing conduct.

According to the recent 48-page complaint, Anthropic clearly considers the previous settlement to be "just the cost of doing business." The plaintiffs argue that a $1.5 billion penalty is not large enough to impact a company that has parlayed its mass infringement into a staggering $2-trillion valuation. Anthropic has not yet released a public comment regarding this new music publishing lawsuit.