William Binney Explains NSA Surveillance Using Snowden's Documents
Former NSA employee—not technical director, as the link says—explains how NSA bulk surveillance works, using some of the Snowden documents. Very interesting.
EDITED TO ADD (10/4): Apologies to Binney for downgrading his role at the NSA. He was not the technical director of the NSA, which is what I was thinking of, but he was a technical director at the NSA:
“In ’97, I became the technical director of the geopolitical—military
geopolitical analysis and reporting shop for the world, which was about
6,000 people,” Binney told Frontline.
Whatever the case, he does know what he’s talking about when he talks about NSA surveillance.