One of my favorite movies is the Will Smith and Gene Hackman flick 'Enemy of the State' (1998) which does a good job of explaining why we should be concerned about abuse of surveillance powers, even if we've done nothing wrong. (Without his knowledge, video evidence of a crime is given to a lawyer who finds himself at the center of an abuse of government powers as officials try to recover the video.)
Yesterday the New York Times reported that "The National Security Agency intercepted private e-mail messages and phone calls of Americans in recent months on a scale that went beyond the broad legal limits established by Congress last year". And I was amused by the sometimes naive and sometimes hysterical comment in blogs!
At one level, we should have nothing to worry about from NSA because many of us allow Google to store and index and search details of our emails; and now also our phone calls. But that lack of concern assumes I'm OK to trust Google's famous motto, "Don't be evil."