> being allowed to train on any data that you can legally obtain ought to be a right for anyone.

I have the opposit viewpoint to the extreme. They shouldn't be allowed to even read that data until they are very clear about what they will or not do with it.

Can they publish it? Can they store it? Can they use the information in it on prediction markets? Etc.

Humans reading texts historically come with little negative consequences, but machines reading and processing texts en masse is more dangerous and should be regulated.