JUDY WOODRUFF: Now to a close look at the U.S. governments surveillance programs.

Its the subject of tonights Frontline on PBS, the first of a two-part series titled The United States of Secrets. Their reporting focuses on inside accounts of the controversial spying operations put in place after the attacks of September 11, 2001.

NARRATOR: It didnt take long for clues to emerge that something much bigger was going on.

WILLIAM BINNEY, Former National Security Agency Technical Director: They started seeing stacks of servers piled in corners and so forth.

So we had to walk way around all this hardware that was piling up out there. And so we knew, you know, something was happening.

JAMES BAMFORD, Author, The Shadow Factory: The Ultra-Secret NSA From 9/11 to the Eavesdropping on America: All of a sudden, people who normally would communicate with each other were keeping secret this new operation of some sort.

NARRATOR: Dozens of NSA employees were sworn to secrecy, but before long, details were leaked to Drake.

THOMAS DRAKE, Former National Security Agency Senior Executive: I had people coming to me with grave concerns of, what are we doing, Tom? I thought were supposed to have a warrant. Im being directed to deploy whats normally foreign intelligence, outward-facing equipment, Im being now directed to place it on internal networks.

NARRATOR: At the same time, Bill Binney and the ThinThread team heard that the program was using ThinThread, but stripping out the privacy protections.

JANE MAYER, The New Yorker: What theyre hearing is that the program they designed is in some form being put into use, but without the protections that they had designed in.

Read the rest here:

Former NSA director: Having surveillance tools revealed puts U.S. in greater harm