A group of bestselling authors including John Grisham, George R.R. Martin and Jodi Picoult joined The Authors Guild, a professional organization for writers, in filing a proposed class action lawsuit against ChatGPT developer OpenAI in the Southern District of New York on Tuesday.

The suit accuses OpenAI of engaging in a “systematic course of mass-scale copyright infringement that violates the rights of all working fiction writers and their copyright holders equally” by harming the market for the authors’ works.