On 8 August 1975, NSA Director Lt General Lew Allen admitted to the Pike Committee of the US House of Representatives that :

"NSA systematically intercepts international communications, both voice and cable" He also admitted that "messages to and from American citizens have been picked up in the course of gathering foreign intelligence".

At a later hearing, he described how NSA used "'watch lists" an aid to watch for foreign activity of reportable intelligence interest".8

US legislators considered that these operations might have been unconstitutional. During 1976, a Department of Justice team investigated possible criminal offences by NSA. Part of their report was released in 1980 It described how intelligence on US citizens, known as MINARET "was obtained incidentally in the course of NSA's interception of aural and non-aural (e.g, telex) international communications and the receipt of GCHQ-acquired telex and ILC (International Leased Carrier) cable traffic (SHAMROCK)" (emphasis in original).

As in the United Kingdom, from 1945 onwards NSA and its predecessors had systematically obtained cable traffic from the offices of major cable companies - RCA Global, ITT World Communications and Western Union. Over time, the collection of copies of telegrams on paper was replaced by the delivery of magnetic tapes and eventually by direct connection of the monitoring centers to international communications circuits. In Britain, all international telex links and telegram circuits passing in, out or through the country were and are connected to a GCHQ monitoring site in central London, known as UKC1000.

By the early 1970s, the laborious process of scanning paper printouts for names or terms appearing on the "watch lists" had begun to be replaced by automated computer systems. These computers performed a task essentially similar to the search engines of the internet. Prompted with a word, phrase or combination of words, they will identify all messages containing the desired woDuring the 1980s, the NSA developed a "fast data finder" microprocessor that was optimally designed for this purpose. It was later commercially marketed, with claims that it "the most comprehensive character-string comparison functions of anyrds or phrases. Their job, now performed on a huge scale, is to match the "key words" or phrases of interest to intelligence agencies to the huge volume of international communications, to extract them and pass them to where they are wanted. text retrieval system in the world". A single unit could work with:

"trillions of bytes of textual archive and thousands of online users, or gigabytes of live data stream per day that are filtered against tens of thousands of complex interest profiles"9 .

Although different systems are in use, the key computer system at the heart of a modern sigint station's processing operations is the "Dictionary". Every Echelon or Echelon-like station contains a Dictionary. Portable versions are even available, and can be loaded into briefcase-sized units known as "Oratory" 10 . The Dictionary computers scan communications input to them, and extract for reporting and further analysis those that match the profiles of interest. In one sense, the main function of Dictionary computers are to throw most intercepted information away.

In a 1992 speech on information management, former NSA Director William Studeman described the type of filtering involved in systems like ECHELON : 11

"One [unidentified] intelligence collection system alone can generate a million inputs per half hour; filters throw away all but 6500 inputs; only 1,000 inputs meet forwarding criteria; 10 inputs are normally selected by analysts and only one report is produced. These are routine statistics for a number of intelligence collection and analysis systems which collect technical intelligence".

In other words, for every million communications intercepted only one might result in action by an intelligence agency. Only one in a thousand would ever be seen by human eyes.

Sumber: http://www.bibliotecapleyades.net/ciencia/echelon01.htm