No U.S. intelligence agency has ever been under the kind of pressure being faced by the National Security Agency after details of some of its most secret programs were leaked by contractor Edward Snowden. Perhaps because of that pressure the agency gave 60 Minutes unprecedented access to NSA headquarters where we were able to speak to employees who have never spoken publicly before.

Full disclosure, I once worked in the office of the director of National Intelligence where I saw firsthand how secretly the NSA operates. It is often said NSA stands for "never say anything," but tonight the agency breaks with that tradition to address serious questions about whether the NSA delves too far into the lives of Americans.