They monitor phone calls and e-mail with a worldwide surveillance network, watching our every move. A fantasy of conspiracy theorists or an emerging reality? Recently, the National Security Agency’s secret spying system Echelon moved from the shadows into the spotlight. What exactly is Echelon? How can it invade privacy, yet protect liberty? How did this billion-dollar system miss the September 11th attacks? In a riveting hour, we uncover the mysterious, covert world of NSA’s electronic espionage.