In 2013, Snowden showed journalists thousands of top secret documents about U.S. intelligence agencies' surveillance efforts. He's been living in exile in Russia ever since. "People look at me now and they think I'm this crazy guy, I'm this extremist or whatever. Some people have a misconception that [I] set out to burn down the NSA," he says. "But that's not what this was about. In many ways, 2013 wasn't about surveillance at all. What it was about was a violation of the Constitution." Snowden talks about his first hack as a preteen, why he decided to leak the documents, and his 40 days detained in the Moscow airport. His new book is 'Permanent Record.'