NSA Has a 'Time Machine'

The National Security Agency has apparently built a surveillance system capable of recording “100 percent” of a country's telephone calls, according to documents released by Edward Snowden. The RETRO tool, short for retrospective retrieval, enables the agency to rewind and review phone conversations from up to a month back, storing billions of them in a 30-day rolling buffer. According to the classified summary, RETRO allows NSA officials to reach “into the past” to replay the voices from any call without requiring that a person be identified in advance for surveillance. Though RETRO was applied to foreign countries, present and former U.S. officials confirmed a large number of conversations involving Americans were gathered by this means.