A group of writers is suing OpenAI over claims the company illegally used their works to train its AI ChatGPT chatbot, as reported earlier by Reuters. In a lawsuit filed on Friday, Michael Chabon, David Henry Hwang, Rachel Louise Snyder, and Ayelet Waldman allege OpenAI benefits and profits from the “unauthorized and illegal use” of their copyrighted content.

The lawsuit is seeking class-action status and calls out ChatGPT’s ability to summarize and analyze the content written by the authors, stating this “is only possible” if OpenAI trained its GPT large language model on their works. It adds that these outputs are actually “derivative” works that infringe on their copyrights.

“OpenAI’s acts of copyright infringement have been intentional, willful, and in callous disregard of Plaintiffs’ and Class members’ rights,” the lawsuit claims. “OpenAI knew at all relevant times that the datasets it used to train its GPT models contained copyrighted materials, and that its acts were in violation of the terms of use of the materials.”

Chabon, the author of various books like The Amazing Adventures of Kavalier & Clay, was among the over 10,000 authors who signed an open letter that calls for OpenAI, Meta, Google, and other companies to “obtain consent from, credit, and fairly compensate authors” for use in the training of AI models.

Additionally, this most recent lawsuit asks the court to stop OpenAI from engaging in “unlawful and unfair business practices” while awarding the authors damages related to copyright violations and other penalties. The Verge reached out to OpenAI with a request for comment but didn’t immediately hear back.