All user content on Stack Overflow is licensed under a Creative Commons license. SE also provides a regular data dump of all that data. This does make it diffic

All user content on Stack Overflow is licensed under a Creative Commons license. SE also provides a regular data dump of all that data. This does make it difficult to create a robust barrier againt AI companies using that data. They added some crawlers to their robots.txt, but I'm not sure if there are any other technical barriers right now. And as Google is using the data under the CC license in the deal SO announced recently, there doesn't seem to be a license barrier either. So I don't see how SE could robustly enforce it, though maybe that isn't necessary anyway.