The current #Twitter rumors are that they are planning to require all users to accept personalized ads. Also that unless subscribed to Blue, location data must also be shared. Again, these are rumors, and offhand I'd say they'd be likely to run afoul of various existing or soon to be laws in the U.S. and/or EU as described. Nor would I expect them to be accepted quietly by most remaining users. Would Elon even be nuts enough to try something like this? Don't answer, it's an academic question. But really, who knows?