And for private comms, they have filters that filter them out for US citizens, as the Snowden leaks show.
LOL when people find out that the Snowden leaks actually show the NSA protecting privacy rights of US citizens, in a top-secret program.
You seem to be taking government descriptions at face value, despite documented evidence to the contrary.
Consider the possibility that the government you seem to place absolute trust in is not, in fact, perfect.
So we make an agreement and build a third-party that has oversight over both of us.
Or do you expect me to trust you?
Let's make this concrete, instead. Anyone can, today, using off-the-shelf software, store information such that only someone with a passphrase can access it, and such that all the computing power in the world would take centuries to access it without the passphrase.
In such a scenario, I don't expect anyone to "trust" anyone, or to need to. (Modulo the issue of trusting the software to be properly implemented, which is a separate discussion but has some plausible solutions.) Instead, I expect that the software in question will prevent unauthorized access, as it was designed to do.