> Investigate steganography. Otherwise they will just make using particular applications servicws illegal and selectively enforce it.

This isn't quite accurate. It's hard to ban things that are widely used.

Because of its design, it's very difficult to censor email. You could order some large provider to do it but then people could use a different one. You can get email for free from a provider in another jurisdiction. It's not that hard to start a new one. Trying to ban interoperability with mail servers in other countries would cut you off from the world. It creates a cost for a government that wants to do it, which is a deterrent, and even if they try it's hard to enforce.

That isn't what happens when everyone is using Facebook, because then a sufficiently major government can just order Facebook to do whatever authoritarian thing under threat of criminal penalties and there is no switching to another provider or operating your own Facebook server while still being able to communicate with the people using the existing system.

You want authoritarianism to have legal friction and technological friction against it. They're not alternatives to each other, they're checks and balances.