US NSA chief: Programs prevented over 50 potential terror acts

General Keith Alexander, the director of the US National Security Agency, said on Tuesday that the NSA's data gathering programs had prevented potential terrorist attacks more than 50 times since Sept. 11, 2001.

"In recent years these programs, together with other intelligence, have protected the US and our allies from terrorist threats across the globe to include helping prevent ... potential terrorist events over 50 times since 9/11," he said in testimony to the US House of Representatives intelligence committee. (Reuters)