A class action lawsuit filed by artists who allege that Stability, Runway, and DeviantArt illegally trained their AIs on copyrighted works can move forward, but only in part, the presiding judge decided on Monday. In a mixed ruling, several of the plaintiffs’ claims were dismissed while others survived, meaning the suit could end up at trial. That’s bad news for the AI makers: even if they win, it’s a costly, drawn-out process where a lot of dirty laundry will be put on display. And they aren’t the only companies fighting off copyright claims — not by a long shot .