Mother Jones 
August 19, 2013
The official, John DeLong, the N.S.A. director of compliance, said that the number of mistakes by the agency was extremely low compared with its overall activities. The report showed about 100 errors by analysts in making queries of databases of already-collected communications data; by comparison, he said, the agency performs about 20 million such queries each month.
Holy crap. They perform 20 million surveillance queries per month? On the bright side, if you assume that their internal auditing really does catch every “incident,” it means they have a violation rate of about 0.001 percent. On the less bright side, they perform 20 million surveillance queries per month.
That’s genuinely hard to fathom. Is some of that automated? Or is that truly 600,000-plus human queries each and every day? The mind boggles.