The National Security Agency, which would prefer to keep a low profile, got a lot of publicity during the Bush Administration. In 2005 the nation learned that as a post-9/11 reflex, President Bush had authorized the NSA to wiretap the phone and email communications of U.S. citizens. A new NOVA documentary, “The Spy Factory,” details how the NSA could have prevented the 9/11 attacks and how it has subsequently violated the privacy of millions of Americans. Joining us to talk about the NSA is journalist James Bamford. He is the writer and co-producer of the NOVA documentary, which is based on his book, The Shadow Factory.