Music publishers drop vicarious claim against Anthropic after Cox ruling

Major music publishers walked back one of their biggest legal weapons against Anthropic. The plaintiffs voluntarily dismissed their vicarious infringement claim, and Judge Eumi K. Lee signed off on the move. The reason traces straight back to a Supreme Court ruling that reshaped how copyright cases get argued.

What the publishers walked back

The publishers, led by Concord, sued Anthropic over its Claude AI models in a complaint filed this past January. One charge accused the company of vicarious liability for infringement by its users and licensees, pointing to protected lyrics showing up in Claude outputs.

“Anthropic has refused to take reasonable steps to prevent the widespread infringement by users of its AI models,” the plaintiffs wrote in the original filing. Judge Lee approved the voluntary dismissal of the claim without prejudice, as reported by Digital Music News. The publishers then submitted an amended complaint, identical to the prior version except for the removal of the vicarious component.

The Cox ruling reshaped the playbook

This did not come out of nowhere. Last month, the publishers also dropped contributory and vicarious claims, with prejudice, from an older and technically separate suit against Anthropic.

Both retreats follow the unanimous Supreme Court decision in favor of Cox Communications, a marathon major-label infringement fight. The ruling narrowed the scope of secondary liability, the legal theory that holds one party responsible for someone else’s infringement.

The precedent is rippling well past this case. It surfaces in several internet-provider cases, in Epidemic Sound’s long-running battle with Meta, in a showdown with stream-ripper Yout, and in a copyright clash with X. Rights holders are reading the same signal everywhere: secondary liability claims got harder to win overnight.

A torrenting claim still targets the founders

The publishers did not fold. A contributory infringement claim survives in the newer suit, reworked to focus on alleged “contributory infringement by torrenting” by Anthropic co-founders Dario Amodei and Benjamin Mann.

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Dr. Amodei and Mr. Mann each knew that they were directing the Anthropic employees working under them to make unlawful copies from known pirated sources.

That framing echoes earlier publisher claims about Anthropic sourcing material from pirated lyric and sheet-music sites. The direct infringement claims, the ones tied to training Claude on copyrighted compositions, are untouched. Those remain the core of the fight, and they head toward the next phase with the heavier secondary-liability theories stripped away.

What this means for the music industry

For rights holders, the Cox decision is a real setback. Suing the platform for what its users do is now a steeper climb, so the pressure shifts to proving direct infringement in the training data itself.

That puts the spotlight back on how these models were built. Did the company copy protected works to train Claude, and from where? The torrenting claim against the founders keeps that question pointed at named individuals, not a faceless company.

The pattern is bigger than Anthropic. The same training-data fight drives the cases against AI music generators, including Sony’s expanding suit against Udio. Every one of them now turns on the same narrow question Cox left standing.