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.