They hear everything.

If you made a phone call today or sent an e-mail to a friend, there's a good chance what you said or wrote was captured and screened by the country's largest intelligence agency. The top-secret Global Surveillance Network is called Echelon, and it's run by the National Security Agency and four English-speaking allies: Canada, Great Britain, Australia and New Zealand. The mission is to eavesdrop on enemies of the state: foreign countries, terrorist groups and drug cartels. But in the process, Echelon's computers capture virtually every electronic conversation around the world.