geoffry mutai retained the title. some of america's best-kept secrets are out. by now, most of the world has heard the name edward snowden. the former national security agency contractor who released thousands of classified documents about government surveillance in one of the most significant leaks in u.s. history. he's been charged with espionage and has been living in russia under temporary asylum. the american journalist at the center of the story lives in brazil. >> we've had to come to rio to speak to glenn greenwald. he hasn't returned to the united states since he broke the story about the nsa surveillance programs for fear of being prosecuted. >> the nsa's goal really is the elimination of privacy globally. it is literally a system designed to monitor all forms of human behavior inside the united states, which is the ultimate surveillance state. >> last december, glenn greenwald received an email from a person who didn't identify himself. >> we still didn't know who he was, where he worked, but he was saying he had access to large amounts of very sensit