Did the NSA catch hordes of these evil al-qaeda types with their dragnet? No. Were any of these card-carrying al-qaeda terror operatives given due process? No.
There are logical fallacies that we must endeavour to see through. Did the spy dragnet keep the al-qaeda menace at bay? Originally there were supposed to be tens of thousands of al-qaeda terror operatives in sleeper cells. They said the same about the Russians a generation earlier. It wasn't so.
There may be fancy computers at Fort Mead but these still cost money. Money that could have been spent on infrastructure that benefited the citizens. There is opportunity cost, many people have actually died in collapsed bridges since the NSA went crazy.
That money definitely could've been spent on infrastructure that benefited the actual citizens of this country and actually saved lives. Unfortunately a great part of American culture is pure jingoism and war propaganda, so nothing changes.
I do find it interesting how people find reasons to believe a lie, the lie being that the post 9/11 spying wasn't on the domestic population just to make sure there was no dissent. With a population that believes the lie then things are kind of doomed. A dark age happens. People find justifications to believe it ain't so. In a unipolar world this becomes a lot more interesting. In previous times there was an 'other' out there, the people in Germany could tune into propaganda from the West, this propaganda could be true facts and it would undermine the regime, Nazi or Stasi if too many people were in on it. In a unipolar world there isn't this possibility.
There is also a trust problem between government and people. In former times gentlemen didn't read each other's mail. Acceptance of otherwise is a betrayal of trust. You have to have good reason to snoop. What was the good reason and what was the excuse in the post 9/11 world? Fear.