A large part of the answer has to do with how the media has presented or ignored it.
The U.S. national media (TV networks, NYTimes, etc.) have pretty much focused on the plight of Snowden and ignored their duty to follow up on Snowden's allegations. They report what Snowden has said, but have done little investigative journalism of their own to invalidate, confirm, or expand on Snowden's words. The few stories that have come out since (google, facebook, etc. helping NSA) were dumped in their laps. I think they would liked to have buried the whole affair but couldn't because it was getting so much attention from non-U.S. media. They are so used to "reporting" to sway public perception and opinion against this type of thing. Now they have a situation where public opinion is already firmly outraged about it, but they don't want to fan the flames because it looks really bad for Obama and they have so much invested in him.
Sometimes I wonder how much of this sort of developing process is the result of the following type of emerging reality:
A) NSA/CIA Guy: "I want to have a cool nice job in an air conditioned building staring at a computer screen. My gosh - WAY BELOW ME to be out on the streets in a hostile country, in a disguise, handing money over for dirty work, late at night."
B) REPORTER: "I want to scrape stories from the Internet, from Twitter and stuff like that. The AP and Reuters and head office sends most of the stuff to me anyway. It's an easy, fun life. What? Me go out and dig stories up? Talk to people? Research? Hey, no way...that's like hard, man."
C) ....
You get the idea. I don't have to continue with University Prof, Average Consumer, etc.
