Anthropic has reached a settlement with a group of authors over the use of pirated books to train its AI model 'Claude,' but some authors have refused to settle.

On July 20, 2026, local time, the U.S. District Court for the Northern District of California approved a settlement between Anthropic, an AI development company, and the plaintiffs in a lawsuit filed by a group of authors alleging that Anthropic used data from pirated websites for AI training.

Bartz v. Anthropic PBC, 4:24-cv-05417 – CourtListener.com
https://www.courtlistener.com/docket/69058235/bartz-v-anthropic-pbc/

US judge approves Anthropic's $1.5 billion settlement of copyright lawsuit | Reuters
https://www.reuters.com/world/us-judge-approves-anthropics-15-billion-settlement-copyright-lawsuit-2026-07-20/

Anthropic’s Book-Piracy Settlement Wins Final Court Approval – Unite.AI
https://www.unite.ai/anthropics-book-piracy-settlement-wins-final-court-approval/

In 2024, three American authors filed a lawsuit against Anthropic in the U.S. District Court for the Northern District of California , alleging that the company illegally used hundreds of thousands of copyrighted books in developing its AI model, 'Claude.' In this lawsuit, the authors sought damages from Anthropic, claiming that the company used pirated datasets of copyrighted content to train Claude and profited from it, potentially earning billions of dollars.

In 2025, a ruling was made stating that 'AI companies do not need the author's permission to train AI with legally acquired books,' but Anthropic's use of data from pirated websites was criticized .

Judge William Alsup of the U.S. District Court for the Northern District of California stated that 'Anthropic's actions of downloading more than 7 million books from pirated sites and building a central library are not fair use,' and also criticized Anthropic for continuing to retain pirated data in its library.

In a lawsuit focusing on the use of pirated data to train an AI model, a settlement was reached between Anthropic and the plaintiffs regarding 'more than 480,000 pieces of pirated content that Anthropic used to train its AI.' The settlement agreement stipulated that Anthropic would pay a total of $1.5 billion (approximately 244 billion yen) in compensation, and the affected authors would be able to receive $3,000 (approximately 488,000 yen) for each piece of work used by Anthropic.

Anthropic to pay over 220 billion yen in settlement for copyright infringement lawsuit - GIGAZINE

However, on September 8, 2025, shortly after the settlement was reported, Judge Al-Sap rejected the motion to approve the settlement. In citing this, Judge Al-Sap pointed out problems with the list of works covered by the settlement agreement and the process of notifying potential class action participants, as well as concerns that the lawyers may have pushed the agreement through by imposing conditions on the authors.

Judge puts a stop to settlement agreement in class-action lawsuit over copyright infringement involving Anthropic - GIGAZINE

Subsequently, on September 25, Judge Al-Sap provisionally approved the settlement proposal, but after that, he was to decide whether to give final approval, after setting a period for notifying affected authors and accepting the submission of claims. In fact, some authors objected to the settlement proposal, arguing that 'the settlement amount is insufficient,' 'the fees for the plaintiffs' lawyers are excessive,' and 'some copyright holders are unfairly excluded.'

Then, on July 20, 2026, Federal District Judge Araceli Martinez-Holguin rejected the motion against the settlement proposal, formally approving the settlement between Anthropic and the plaintiffs. This represents the largest settlement ever reached in a U.S. copyright lawsuit.

According to the plaintiffs' legal team, settlement claims have already been filed for more than 440,000 titles, representing over 90% of the affected works. This far exceeds the typical 10% seen in general class-action lawsuits. Anthropic plans to contribute a total of $1.5 billion in settlement payments in four installments to a fund for the more than 480,000 books covered by the settlement, in accordance with the terms set by the legal team.

Furthermore, some authors and publishers still oppose the settlement and have withdrawn from it, filing their own lawsuits against Anthropic, which remain ongoing as of the time of writing.