While I'm certainly no fan of the surveillance state, lets be frank: Petraeus took down Petraeus.
He was a man in a high visibility position that demanded integrity in both his personal and professional life and he compromised himself for the sake of an orgasm.
One of the first things an officer learns as a cherry lieutenant is that you live in a fishbowl.
I just read on one of the threads that someone has admitted they listened in on the Military having phone sex with people back home.