ECHELON is a name used in global media and in popular culture to describe a signals intelligence (SIGINT) collection and analysis network operated on behalf of the five signatory states to the UK–USA Security Agreement (Australia, Canada, New Zealand, the United Kingdom, and the United States, known as AUSCANNZUKUS). It has also been described as the only software system which controls the download and dissemination of the intercept of commercial satellite trunk communications.
ECHELON was reportedly created to monitor the military and diplomatic communications of the Soviet Union and its Eastern Bloc allies during the Cold War in the early 1960s, but since the end of the Cold War it is believed to search also for hints of terrorist plots, drug dealers’ plans, and political and diplomatic intelligence.
The system has been reported in a number of public sources. Its capabilities and political implications were investigated by a committee of the European Parliament during 2000 and 2001 with a report published in 2001, and by author James Bamford in his books on the National Security Agency of the United States.
In its report, the European Parliament states that the term ECHELON is used in a number of contexts, but that the evidence presented indicates that it was the name for a signals intelligence collection system. The report concludes that, on the basis of information presented, ECHELON was capable of interception and content inspection of telephone calls, fax, e-mail and other data traffic globally through the interception of communication bearers including satellite transmission, public switched telephone networks (which once carried most Internet traffic) and microwave links.
Bamford describes the system as the software controlling the collection and distribution of civilian telecommunications traffic conveyed using communication satellites, with the collection being undertaken by ground stations located in the footprint of the downlink leg.