I don't know if we'll ever know the whole truth, but I do know that none of us know enough right now to make a judgement.
What I really wonder is what our Congress has been doing for oversight in the area of electronic surveillance of all types. If Congress doesn't hold up their end, then they are every bit as culpable as the Executive branch, because they wrote and passed the authorization laws in the first place. If they had any doubts at all about the programs, they should have called for it to be curtailed until it passed muster with the Constitution.
I still say that only a fool would really think that your phone calls, emails, tweets, or whatever are private. Assume you're being watched and listened to and suit yourself what you share with others--and the guvmint spooks.