James R. Clapper — American Public Servant born on March 14, 1941,

James Robert Clapper, Jr. is a retired lieutenant general in the United States Air Force and is currently the Director of National Intelligence. He served as director of the Defense Intelligence Agency from 1992 until 1995. He was the first Director of Defense Intelligence within the Office of the Director of National Intelligence and simultaneously the Under Secretary of Defense for Intelligence. Clapper has held several key positions within the United States Intelligence Community. He served as the director of the National Geospatial-Intelligence Agency from September 2001 until June 2006... (wikipedia)

In the end, we will never, ever be able to guarantee that there will not be an Edward Snowden or another Chelsea Manning because this is a large enterprise composed of human beings with all their idiosyncrasies.
What I said was, the NSA does not voyeuristically pore through U.S. citizens' e-mails. I stand by that.