The Intercept has published an article by James Bamford detailing how he blew the whistle on the NSA back in 1975, and how he fought the NSA and the White House to get his book published.
I soon learned that there was one major advantage to being first: The NSA had grown so confident that no one would ever dare to write about it that it had let its guard down. I would occasionally drive up to the agency, park in the executive parking lot, walk in the front door to the lobby, get some coffee and have a seat. All around me were employees from the CIA and foreign intelligence agencies, all waiting to be processed for their NSA visitor’s badge. As I read my paper and sipped my coffee, I quietly listened to them chat away about signals intelligence operations, new listening posts, cooperative agreements, and a host of other topics. No one ever asked who I was or why I was there. In the parking lot, I copied the license plate numbers of the dozen cars parked closest to the front entrance, then ran the numbers at the registry of motor vehicles. The result was a Who’s Who of the NSA’s leadership, as well as the liaison officers from America’s so-called Five Eyes surveillance partners: England, Canada, Australia, and New Zealand.
It’s very much worth reading.