What is an AI watermark, and what does it actually prove?

AI-generated content isn’t always easy to spot, which can lead to tricky situations, to put it lightly. As a result, most of the major AI companies now automatically add watermarks to the images, videos, and—increasingly—text their models generate. If you create an image with ChatGPT or get Claude to write your press release (or do your homework), it may now include a secret sign that it was AI-generated—or, at the very least, that you used AI to assist you.