A Microsoft logo and sign are seen outside the company's main office in Redmond, Washington. (AP Photo/Jason Redmond, File)
A group of well-known authors has filed a lawsuit against Microsoft, accusing the tech giant of using their books—without their permission—to train its artificial intelligence system named Megatron. The lawsuit, filed in a New York federal court on Tuesday, claims that Microsoft used illegal digital copies of books to improve the performance of its AI model.
The authors behind the case include Pulitzer Prize winner Kai Bird, popular essayist Jia Tolentino, and historian Daniel Okrent, among others. According to them, Microsoft allegedly gathered around 200,000 pirated books to feed into its Megatron AI. This model is designed to produce human-like responses to text-based prompts. The writers argue that their copyrighted work was used to build a system that not only learns from but also imitates their style, tone, and themes.
This case is part of a growing wave of legal challenges aimed at tech companies over the unauthorized use of creative works in developing AI technologies. Meta, Anthropic, and OpenAI—Microsoft's AI partner—are also facing similar lawsuits from authors, journalists, and copyright owners.
Interestingly, this legal move comes just one day after a California judge made a notable ruling in a separate case involving Anthropic. The judge found that the AI firm’s use of copyrighted materials might qualify as “fair use” under U.S. copyright law. However, the court also hinted that Anthropic could still be held responsible if the books were obtained from illegal sources. This ruling is considered the first legal decision in the U.S. addressing whether copyrighted materials can legally be used to train generative AI systems.
So far, Microsoft has not commented on the latest lawsuit. The authors’ lawyer also refused to provide any additional remarks.
The authors claim that Microsoft’s actions go beyond technical training—they believe their work has been taken to create a model capable of producing writing that closely mirrors their own. According to the lawsuit, Megatron not only borrows their language and ideas but can reproduce entire styles and narratives shaped by years of effort and creativity.
Tech companies, on the other hand, argue that their use of copyrighted material is allowed under the concept of “fair use,” especially when the end product is a new or transformative creation. They also warn that making them pay for every piece of content could severely slow down the growth of artificial intelligence.
The authors are seeking a court order to stop Microsoft from using their books in this way. They are also asking for financial compensation—up to $150,000 for each book that was allegedly used without permission.
As legal debates heat up, this lawsuit may become a key moment in deciding how the creative world and tech industry will coexist in the age of artificial intelligence.
