By Glenn Greenwald. In May 2013, Glenn Greenwald set out for Hong Kong to meet an anonymous source who claimed to have astonishing evidence of pervasive government spying and insisted on communicating only through heavily encrypted channels. That source turned out to be the 29-year-old NSA contractor Edward Snowden, and his revelations about the agency’s widespread, systemic overreach proved to be some of the most explosive and consequential news in recent history, triggering a fierce debate over national security and information privacy. As the arguments rage on and the government considers various proposals for reform, it is clear that we have yet to see the full impact of Snowden’s disclosures. Metropolitan Books (2014), English, Hardcover: 272 pages pages.