National Security Agency Director Gen. Keith Alexander is sworn on Capitol Hill on Sept. 26. Carolyn Kaster/AP hide caption
Gen. Keith Alexander
Gen. Keith Alexander, director of the National Security Agency, in June 2013. Mark Wilson/Getty Images hide caption
U.S. Army Gen. Keith Alexander, commander of the U.S. Cyber Command, director of the National Security Agency (NSA), testifies during a Senate Appropriations Committee hearing on Capitol Hill, on Wednesday. Mark Wilson/Getty Images hide caption
Sean Joyce, right, deputy director of the Federal Bureau of Investigation testifies before the House Select Intelligence Committee on Tuesday. Win McNamee/Getty Images hide caption
U.S. Army Gen. Keith Alexander, commander of the U.S. Cyber Command, director of the National Security Agency (NSA), testifies during a Senate Appropriations Committee hearing on Capitol Hill, on Wednesday. Mark Wilson/Getty Images hide caption