NSA Confirms Dragnet Phone Records Collection & Admits It Was Key In Stopping Just 1 Terror Plot 2/2

Testifying before the Senate on Wednesday, National Security Agency Deputy Director John Inglis conceded that the bulk collection of phone records of millions of Americans under Section 215 of the USA PATRIOT Act has been key in stopping only one terror plot -- not the dozens officials had previously said.

Ahead of Wednesday's Senate hearing, the Obama administration released three heavily censored documents related to its surveillance efforts, but the White House has refused to declassify the legal arguments underlying the dragnet or the original rulings by the U.S. Foreign Intelligence Surveillance Court, on which the released order to collect phone records was based.

Meanwhile the head of the NSA, General Keith Alexander, was repeatedly interrupted by critics of government surveillance in a speech Wednesday before the Black Hat conference, a gathering of hackers and cybersecurity professionals in Las Vegas.

We're joined by two guests: Spencer Ackerman, national security editor at The Guardian; and James Bamford, an investigative reporter who has covered the National Security Agency for three decades after helping expose its existence in the 1980s.