FORT MEADE, Md. — The director of the National Security Agency, Gen. Keith B. Alexander, said in an interview that to prevent terrorist attacks he saw no effective alternative to the N.S.A.’s bulk collection of telephone and other electronic metadata from Americans. But he acknowledged that his agency now faced an entirely new reality, and the possibility of Congressional restrictions, after revelations about its operations at home and abroad.
N.S.A. Director Gives Firm And Broad Defense Of Surveillance Efforts