The agencies also specify combinations of these keywords to help sift out
communications of interest.
For example, they might search for diplomatic cables containing both the
words 'Suva' and 'aid', or cables containing the word 'Suva' but NOT the
word 'consul' (to avoid the masses of routine consular communications).
It is these sets of words and numbers (and combinations of them), under a
particular category, that are placed in the Dictionary computers.
The whole system was developed by the NSA.
P51-
The only known public reference to the ECHELON system was made in relation to
the Menwith Hill station. In July 1988, a United States newspaper, the
Cleveland Plain Dealer, published a story about electronic monitoring of
phone calls of a Republican senator, Strom Thurmond. The alleged monitoring
occurred at Menwith Hill.
Margaret Newsham worked at Menwith Hill as a contract employee of Lockheed
Space and Missiles Corporation. She is said to have told congress staff that,
while at Menwith, she was able to listen through earphones to telephone calls
being monitored.
When investigators subpoenaed witnesses and sought access to plans and manuals
for the ECHELON system, they found there were no formal controls over who
could be targeted; junior staff were able to feed in target names to be
searched for by the computer