U.S. District Judge Sidney Stein of the Southern District of New York on Monday denied a motion from plaintiffs pursuing copyright infringement claims against ChatGPT developer OpenAI in California to intervene in similar litigation in New York.

Stein is presiding over a set of four cases against OpenAI filed by professional writers including several Pulitzer Prize winners; The Authors Guild, a professional organization for writers; and The New York Times. Microsoft, an OpenAI investor, is also named as a defendant in the New York cases.