Music publishing titans Sony Music Publishing and Warner Chappell Music filed a multibillion-dollar copyright infringement lawsuit against artificial intelligence (AI) developer Anthropic, escalating a nationwide legal battle over how AI systems source their training data.

The complaint, filed late Friday in the U.S. District Court for the Northern District of California, accuses the Amazon.com Inc.-backed startup and its co-founders, CEO Dario Amodei and Benjamin Mann, of orchestrating a systemic, large-scale campaign of copyright theft to build and power its flagship AI model, Claude.

Music publishers accuse Anthropic of unlawfully torrenting, scraping, and duplicating tens of thousands of protected musical compositions. The suit highlights iconic catalog tracks including “Ain’t No Mountain High Enough,” “Eye of the Tiger,” “Uptown Funk,” “September,” and Taylor Swift’s “Paper Rings.”

According to court filings, Anthropic bypassed official licensing channels by scraping lyrics from licensed digital platforms and downloading pirated datasets through torrent networks. The music giants cite evidence indicating executive involvement in obtaining millions of unauthorized files.

Additionally, the publishers allege that Claude stores these works and can output copyrighted lyrics verbatim upon user prompting, undermining streaming royalties and creator livelihoods.

The joint lawsuit seeks maximum statutory damages of up to $150,000 per willful infringement, alongside $25,000 per violation for stripping copyright management metadata. With tens of thousands of songs implicated, Anthropic faces potential damages stretching deep into the billions of dollars. The plaintiffs are also requesting a jury trial and demanding the court order the destruction of all illicitly acquired training files.

Anthropic quickly pushed back against the allegations. “We disagree with the publishers’ claims and we intend to defend ourselves robustly in court,” a company spokesperson said.

The legal challenge marks a significant consolidation of the music industry’s stance against unlicensed AI scraping. Universal Music Group, Concord Music Group, and ABKCO previously targeted Anthropic in prior litigation, meaning all three major music conglomerates are now locked in federal court battles with the AI lab.

The publishers’ strategy builds on a critical precedent established in Bartz v. Anthropic, where a judge ruled that while AI model training on legally acquired text may constitute fair use, harvesting content from pirated “shadow libraries” is unlawful piracy. That case culminated in a historic $1.5 billion settlement against Anthropic.

The latest action underscores the music industry’s firm position: AI innovation can thrive alongside human creativity, provided developers operate through legitimate, permission-based licensing agreements rather than unauthorized extraction.