] "ECHELON is the term popularly used for an automated
] global interception and relay system operated by the
] intelligence agencies in five nations: the United States,
] the United Kingdom, Canada, Australia and New Zealand (it
] is believed that ECHELON is the code name for the portion
] of the system that intercepts satellite-based
] communications)."

This is the site maintained by the ACLU that collates known information about the Echelon surveillance system