I am so sick of seeing that same goddamned argument.
"I have nothing to hide."
Yes, you do. Don't lie. Everyone does. Either that or a time will come when you will have something really pivotal to hide.
What people don't realize is just how this bastion of information will rain down upon them in the future. Rising politicians and social activists will instantly be smeared and destroyed by unearthing an old online post or email they've sent in the past. A foreign corporation that threatens the monopoly or stability of a different native corporation can persuade the NSA to release information that will tarnish the foreign corporation's image and send them to hell.
Finally, the US government is divided enough as it is. The FBI, CIA, NSA, DEA and so on are practically autonomous entities. Yeah, well, things are only going to get worse as agencies try to kill each other with information.