Bartz v. Anthropic PBC

Class action by authors who allege their books were used without permission to train Anthropic's Claude models. Authors Andrea Bartz, Charles Graeber, and Kirk Wallace Johnson sued Anthropic for using their copyrighted books to train Claude AI models without permission.

The case challenged Anthropic's practice of building a "central library of all the books in the world" by purchasing millions of books, digitising them, and downloading over seven million pirated books from shadow library sites like Library Genesis. On 23rd June 2025, Judge William Alsup issued a landmark split ruling that distinguished between legitimate AI training and digital piracy. The court granted summary judgment for fair use regarding training Claude on copyrighted works, calling it "spectacularly transformative" and analogising it to teaching humans to write. The judge also permitted Anthropic's digitisation of legally purchased books as format-shifting fair use. However, the court rejected fair use for Anthropic's acquisition and retention of pirated books, allowing the case to proceed to trial on this issue. The ruling exposed Anthropic to potential statutory damages of up to $150,000 per work for an estimated seven million pirated books.

On 27 August 2025, the Parties reached a settlement which was approved by the court during September 2025. Amongst the settlement terms is an agreement for Anthropic to pay at least US$1.5bn plus interest to the full class of 500,000 Plaintiffs. Anthropic has also agreed to destroy all works illegally downloaded from pirate/torrent sites.

This summary is provided for educational and research purposes only and does not constitute legal advice. Allegations described are those made in the filings. Please consult the underlying source documents.