The same can be said for every method of communication in history. Security agencies have the technical capabilities to record your telephone conversations, read your mail, and listen to your private conversations. Yet we manage.
There are so many frightening powers out there, trying to prevent them from existing is a complete waste of effort. You simply cannot make it technologically impossible to shoot you with a bullet, or snoop in your house, or track your car. This is why gov't is regulated, and answers to the people. You simply cannot prevent everyone from having the technical capabilities to take the advantage of you.
So, IMO, forget about whether they can or they cannot. Even if you manage to prevent them from breaking strong crypto, if it can be done someone will do it. Focus on controlling what they do with it.
The thing that is fundamentally different about modern surveillance is how automated it can be. Governments have always been able to listen in on phone calls and physical mail, but the limitations of needing a person to actually do these things kept a check on the scope.
When every phone call can go through a voice recognition system and a set of filters to detect anyone talking about Topic X, that's a very different world. The NSA can't hire half the country to spy on the other half, but they can hire a few thousand people to build a computer system to spy on everyone.
There are so many frightening powers out there, trying to prevent them from existing is a complete waste of effort. You simply cannot make it technologically impossible to shoot you with a bullet, or snoop in your house, or track your car. This is why gov't is regulated, and answers to the people. You simply cannot prevent everyone from having the technical capabilities to take the advantage of you.
So, IMO, forget about whether they can or they cannot. Even if you manage to prevent them from breaking strong crypto, if it can be done someone will do it. Focus on controlling what they do with it.