They could it would just make them very, very unpopular. This clearly isn't a hill they're prepared to die on.

The fact that they tried this at all signals how weak this government is though, as well as how blithely unaware they are of it.

No, they couldn't. They could remove it from appstores and block certain domains, and that's it. They couldn't actually stop people from using it.

That'd be enough to get people off it and unwind the network effects keeping people on it.