Warner Bros. is suing artificial intelligence company Midjourney for copyright infringement, alleging that the startup enables its millions of subscribers to create AI-generated images and videos of copyrighted characters like Superman and Bugs Bunny. It’s the third big Hollywood studio to sue Midjourney in Los Angeles federal court after Disney and Universal filed a joint lawsuit in June. Midjourney, based in San Francisco, didn’t immediately respond to a request for comment.