Sony Music Publishing and Warner Chappell v. Anthropic: The Publishers' Claude Lawsuit, Explained

What is the Sony Music Publishing and Warner Chappell lawsuit against Anthropic?

On August 28, 2026, Sony Music Publishing and Warner Chappell Music filed a joint copyright complaint against Anthropic in the US District Court for the Northern District of California. They also named two people: co-founder and CEO Dario Amodei, and co-founder Benjamin Mann.

The publishers call the conduct one of the largest and most blatant ongoing thefts of intellectual property in history, and describe a “brazen campaign of illegally torrenting, scraping, and downloading copyrighted works.” I covered the filing in this piece.

Anthropic rejects the claims. “We disagree with the publishers’ claims and we intend to defend ourselves robustly in court,” a spokesperson told TechCrunch on August 29, 2026.

Who is involved?

Sony Music Publishing and Warner Chappell Music are the publishing arms of two of the three major music companies. Publishing covers the song itself, the composition and lyrics, rather than a particular recording of it. The two lead the case, and a group of affiliated publishers joined them on the filing.

Anthropic is the AI developer behind Claude. Dario Amodei and Benjamin Mann co-founded it, and both are named on two of the four counts.

The publishers are represented by Oppenheim + Zebrak LLP, lead counsel on the Concord case against Anthropic, together with Pryor Cashman LLP.

Why naming Dario Amodei and Benjamin Mann is the unusual part

Copyright suits normally name the company. This one asks a court to reach the founders.

“Dr. Amodei and Mr. Mann are personally liable for their respective roles in this illegal torrenting of pirated copies of Music Publishers’ works from LibGen and PiLiMi,” the complaint states.

Anthropic has already fought this theory once. In the second Concord case it moved to dismiss the personal claim against Amodei on August 6, 2026. That motion is the best available guide to how it will answer here.

What are the four counts in the complaint?

The suit brings four claims:

• Direct infringement by torrenting, against Anthropic, Amodei and Mann
• Contributory infringement by torrenting, against Amodei and Mann. Contributory infringement means helping someone else infringe rather than doing it yourself
• Direct infringement, against Anthropic alone
• Removal or alteration of copyright management information, against Anthropic alone

Copyright management information is the credit block attached to a file: who wrote the song, who owns it, what licence applies. Stripping it carries its own penalty of up to $25,000 for each removal, separate from the infringement damages.

Where the LibGen and PiLiMi allegations come from

The complaint says that in June 2021, Mann used BitTorrent, a file-sharing protocol, to download at least 5 million pirated books from Library Genesis. It says Anthropic employees torrented at least 2 million more from Pirate Library Mirror in July 2022. Sheet music and lyrics sit inside those collections.

Both figures come from findings in Bartz v. Anthropic, the authors’ case, where a judge in the same district described the conduct as “straightforward piracy but at massive scale.”

The filing also quotes internal Anthropic material unsealed in Bartz, including Mann calling LibGen “sketchy AF” and the company’s own Archive Team describing it as a “blatant violation of copyright.”

On the $1.5 billion Anthropic agreed to pay the authors, a settlement I covered when Donald Passman fought to exit it, the publishers wrote that the company “clearly considers that to be just the cost of doing business.”

What are Sony Music Publishing and Warner Chappell asking the court to do?

Three things. Statutory damages of up to $150,000 for each work willfully infringed, plus up to $25,000 for each removal of copyright information. Destruction of every infringing copy. And an account of what went into Claude’s training data.

That third request is the one with reach, because it would put the contents of a frontier model’s training set on the record. You can read the full complaint here.

The publishers are careful to say they are not against the technology. They write that they “recognize the potential of ethical AI technology” and have already signed licences for authorised AI use of their compositions, which matches the industry-wide deals the NMPA signed with Udio and Klay.

How this case fits the other Anthropic lawsuits

Anthropic now faces five publisher actions. Universal Music Publishing Group, Concord and ABKCO filed in October 2023 and again in January 2026, both tracked in Concord v. Anthropic. BMG brought a third case in March 2026 over 493 compositions. Round Hill filed a fourth on August 17, 2026. This is the fifth.

Anthropic has already asked to group the Round Hill complaint with the Concord and BMG actions, calling the claims virtually identical. Whether this case joins that group is the first procedural question worth watching.

What this means for you

• The personal liability theory is the thing to watch. If it survives a motion to dismiss, every AI company’s data-collection decisions become a personal risk for the people who signed off on them.
• These claims sit outside fair use. Torrenting and copyright information removal ask how files were obtained, so a ruling that model output is transformative would not dispose of them.
• Licensing and litigation are running at the same time. The same publishers suing here have signed AI licences elsewhere, which tells you the fight is about terms rather than the technology.

How this fits the bigger picture

Every AI music case now splits into two questions. Does training on unlicensed work need a licence, which fair use will answer. And how were the files obtained in the first place, which fair use cannot reach.

Sony Music Publishing and Warner Chappell built their complaint almost entirely on the second question, then added a third that no music case had pressed before: whether the people who ran the company answer for it themselves.