Music publishers ask a court to order an accounting of Anthropic training data

Case 5:26-cv-09217 was filed in the San Jose division on August 28, 2026. It names three defendants: Anthropic PBC, Dario Amodei and Benjamin Mann. The publishers ask for damages, an injunction and the destruction of infringing copies. They also ask for a description of what the models were trained on, which the earlier class action against Anthropic never produced.

What the complaint alleges

The complaint describes a campaign of illegal torrenting, scraping and downloading of copyrighted works on a massive scale, carried out to develop and operate the Claude models. Every statement in it is an allegation. No court has ruled on any of it.

Two acquisitions are set out by name and date. In June 2021, the complaint says, Mann torrented at least five million pirated books from Library Genesis on Anthropic behalf and at Amodei direction, a figure it takes from the Bartz ruling. In July 2022 the defendants torrented at least two million more from Pirate Library Mirror.

Among those books, the complaint says, were volumes carrying the lyrics and sheet music of hundreds of the plaintiffs compositions, listed in Exhibit A. It names Livin’ On a Prayer, September, Great Balls of Fire, Ramblin’ Man and Hallelujah. It also cites an answer Mann filed in a separate case, in which he stated that he discussed acquiring the Library Genesis data with Amodei and that Amodei approved it.

Four counts, and who each one names

The claims for relief are numbered I through IV, and they do not all point at the same defendant.

• Count I, direct copyright infringement by torrenting, against all three defendants.
• Count II, contributory infringement by torrenting, against Amodei and Mann personally.
• Count III, direct copyright infringement, against Anthropic.
• Count IV, removal or alteration of copyright management information, against Anthropic.

The relief they ask for

The prayer for relief has nine lettered items, from a finding of wilfulness to interest and costs. Four of them decide how far this case reaches.

• Statutory damages of up to $150,000 per work infringed under section 504(c), or actual damages and profits at the publishers election.
• Statutory damages of up to $25,000 for each removal or alteration of copyright management information, under section 1203(c)(3)(B).
• A permanent injunction binding Anthropic, its officers, employees and agents, with Amodei and Mann named among those bound.
• An accounting of the training data, the training methods and the known capabilities of Anthropic models, with destruction of infringing copies under court supervision and a sworn report of compliance.

Why the accounting request is the unusual part

Damages get negotiated. The accounting would require Anthropic to identify the copyrighted works its models were trained on, and to disclose how that data was collected, copied, processed and encoded, including through any third parties engaged to collect or license it.

That puts the composition of a training corpus into a court record. The Bartz class action ended in a payment and left the corpus undescribed. If the court grants item e here, the description becomes part of the case file, and the next plaintiff has a form to copy.

What the complaint builds on

The publishers lean on Bartz v. Anthropic, decided in the same district in 2025. That court found Anthropic had torrented more than seven million copyrighted books from Library Genesis and Pirate Library Mirror, and the class action settled for $1.5 billion. The complaint argues the company treated that sum as a cost of doing business.

It also points to two pending Concord Music Group cases against Anthropic, and to an internal decision from June 2021. Anthropic engineers, the complaint says, rejected one text extraction tool because it left copyright notices standing in page footers, and chose tools that stripped them.