> Would regulation help with that? Right now you can download free models that have been trained on that "stolen" data

We do have regulation against these issues. Companies spent years railing against piracy and IP theft enshrining it into law but now that it's being done by them en masse it's considered acceptable. The reality is that no regulation would help because we don't have regulators willing to enforce it nor do we have a legal system designed to help individuals against mass theft by corporations.