Trust But Verify
Just because the government does so many things that are wrong and just because so many secret things it does are horrible and just because so much to do with so-called "national security" is a huge waste and, of course, because having wars all the time is insane, it does not then logically follow that all the things that are secret that have to do with national security should not be done.
Counted correctly the US spends over a trillion dollars a year on national security. Over 7% of GDP — obviously a lot of people have vested interests. Arguably we could get by with two thirds, perhaps even half that expense with just as good protection if we were to change our foreign policies. No doubt surveillance programs, similarly, are excessively large. But something like them, on some scale, will be an on-going, permanent feature of our government apparatus. Get used to it!
Besides, it's unfair — a mind-boggling exaggeration — to compare surveillance to things like torture. Both occur (occurred) in secret but that's about all they have in common. No little old ladies have complained that because the government made public their Communistic leanings that their church threw them out. Have you seen any reports of wrongdoing from government surveillance? Blackmail? Robbery? Anything? No, because the harm is hypothetical. That doesn't make the potential threat less serious but you have to put things into perspective. The people doing the surveillance realize that if they veer into abuse it will be game over. Nobody is particularly happy with the current standoff between civil libertarians and the government; both sides should relax a little and try to talk.
I would encourage critics of government surveillance to stop for a minute and think about why the government might be so reluctant to talk about its capabilities. Undoubtedly the government can do things that nobody knows about yet and, understandably, it's reluctant to disclose those capabilities out of concern for their effectiveness. Take, for example, a hypothetical. We know that laser interferometry can be used as a kind of microphone. We know that satellites can use lasers in all sorts of ways. Put two and two together. What if NRO, an agency whose existence was only declassified in 1992 and whose budget exceeds both that of the NSA and CIA, could use satellite lasers to listen in on conversations on earth? That would be cool! But suppose further that this capability were being deployed at home... (Before the guys in black overcoats show up to arrest me I want to emphasize that this hypothetical is entirely a product of my own imagination and does not depend whatsoever on anything I may or may not have known from my government service. That's my story, and I'm sticking to it.) Science fiction writers could probably dream up a slew of other capabilities. The point is, what the government gains from revealing such things doesn't necessarily outweigh the advantages to keeping them secret.
It's not enough for the government to say 'trust us.' But some kind of trust will be necessary, perhaps along Reagan's model of 'trust but verify.' Who could verify that the government's surveillance is benign and how they might do it is the question.
NB If you haven't seen it you might enjoy one of my favorite trash films, Enemy of the State (1998), starring Will Smith, Gene Hackman and Jon Voight.