SOMEONE IS LISTENING: The computers in stations around the globe are known, within the network, as the ECHELON Dictionaries. Computers that can automatically search through traffic for keywords have existed since at least the 1970s, but the ECHELON system was designed by NSA to interconnect all these computers and allow the stations to function as components of an integrated whole.
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Read more:
http://cryptome.org/jya/echelon.htm
http://en.wikipedia.org/wiki/ECHELON