"IT BEGAN WITH A TANTALIZING, ANONYMOUS EMAIL: "I AM A SENIOR MEMBER OF THE INTELLIGENCE COMMUNITY." What followed was the most spectacular intelligence breach ever, brought about by one extraordinary man. Edward Snowden was a 29-year-old computer genius working for the National Security Agency when he shocked the world by exposing the near-universal mass surveillance programs of the United States government. His whistleblowing has shaken the leaders...