Microsoft Faces Lawsuit Over AI Training
On June 25, 2025, a group of authors filed a lawsuit against Microsoft, claiming that the tech giant used their books without permission to train its Megatron artificial intelligence model.
Kai Bird, Jia Tolentino, Daniel Okrent, among others, alleged that Microsoft utilized unauthorized digital copies of their works to develop the AI’s capabilities in responding to user prompts. The lawsuit, lodged in New York federal court, adds to a series of significant legal actions that authors, news organizations, and other copyright holders have initiated against technology companies such as Meta Platforms, Anthropic, and Microsoft-supported OpenAI for alleged copyright violations related to AI training.
This complaint emerged just a day after a ruling from a California federal judge, which stated that Anthropic’s use of authors’ materials could be considered fair use under U.S. copyright law. However, the judge noted that Anthropic might still face liability concerning the unauthorized use of the authors’ books. This was a landmark decision regarding the legality of using copyrighted material for generative AI training.
Microsoft representatives did not provide immediate comments regarding the lawsuit, and an attorney representing the authors opted not to make a statement.
The lawsuit highlighted that Microsoft allegedly employed a trove of nearly 200,000 pirated books to train Megatron, which is designed to generate text-based responses. The authors contended that Microsoft’s AI model was not only grounded in the extensive works of numerous creators but was also crafted to replicate styles, voices, and themes from the copyrighted materials it was developed with.
In response, tech companies have maintained that their use of copyrighted content is transformative and falls under fair use. They argue that requiring payment to copyright holders could severely hinder the growth of the AI sector.
The authors have requested a court order to halt Microsoft’s alleged infringement and are seeking statutory damages that could reach up to $150,000 for every work they believe was misused.
