Earlier quoted context omitted.
They systematically violated copyright when they grabbed whole internet to train their models. Do you really believe that they will stop stealing because they signed some funny ToS? Especially when every bit of data they have and competition does not have is making their model better.
People downvote you like you're being paranoid, but we're literally discussing this in a thread that shows how little respect those companies have for any sort of trade secrets.
AI labs can hardly just throw random confidential data into the training and then hope it does not leak into the output of their model in an obvious way.
If that would be found it would destroy their main source of revenue, it could became a major national security or healthcare enforcement matter, and result in criminal investigations.