I think you have forgotten the phrase "absolute power corrupts absolutely." Humans with unchecked access to information (=power) will NEVER be completely trustworthy. Never. It is by definition. That's why we have checks and balances. That's why we had democracy. No one should be absolutely above democracy. But that's what today's NSA is.
You realize these guys (in the NSA) have been using intelligence resources to spy on their girlfriends and neighbors? How much more human and fallible does it get than that?