And yes, they are spying on everybody. They have access to things like cellphone metadata, which to a normal human being is a very clear violation of privacy.
It's also my firm belief that our legal system has been undermining these basic concepts for decades now. It benefits the federal government to make this all very vague, as if modern technology suddenly means you have no expectation of privacy anymore. They've also mixed in some of that wonderfully authoritarian "for purposes of national security".
There's actual lawyers saying these same things, if you'd like someone to properly debate with.