I think we can compare the leaks of Ed Snowden with the Pentagon Papers leaks of Mike Gravel.

Post 9/11 (And even before) the US government began a widespread campaign against US citizens themselves under the guise of the "War on terror". People became so brainwashed that what we were doing was unequivocally "right" and what the other guys were doing was wrong. And it's continued to the point where the general public now thinks that we're the good guy's no matter what, without questioning authority. At the time the Pentagon Papers were leaked, it was the first time in a long time (In my opinion) that the general populous woke up and saw that we were doing some pretty horrendous things. The 3 letter agencies took this to heart, and learned from it. People haven't been taught to think critically in a long time, and that's on purpose.