Just authorize. If you have perfect-forward secrecy, as long as you aren't being man-in-the-middled right now, you're safe.

It's better to have all people doing everything encrypted by default than not.

The goal isn't for one individual to be safe against a targeted NSA attack. That's insane--if the NSA wants you, specifically you are screwed; it simply has far too many resources to bring to bear.

The goal is to make it expensive for the big agencies to do pervasive surveillance. If everybody is encrypting all the time, random peon at Three Letter Agency has to get up from his chair and actually authorize a wiretap, get a warrant, etc. At that point, it's not going to happen unless you've actually done something very wrong.