Project Greenstar
Development started in 1962. First installed by end of 1964.
We devised six experimental units which we placed at representative
cities. Two were placed in Los Angeles because of not only activity in
that area, but also different signaling arrangements, and one was
placed in Miami, tow were originally placed in Newark, NJ, and one was
placed in Detroit, and then about January 1967 moved to St. Louis.
…
There were in each of these locations a hundred trunks selected out of
a large number, and the […] logic equipment would select a
call. There were five temporary scanners which would pick up a call
and look at it with this logic equipment and determine whether or not
it had the proper […] supervisory signals, whether, for example
there was a return answer supervision. When we have a call, we have a
supervisory signal that goes to and activates the billing equipment
which usually we call return answer supervision. That starts the
billing process and legitimizes the call, and if you find voice
conversation without any return answer signal, and that is what it was
looking for, it is an indication, a strong indication, of a possible
black box that the caller called in; and if, for example, you heard
the tell-tale blue box tone […] this was a very strong indication of
illegality because that tone has no normal presence upon our network
at that point.
– Bill Caming, AT&T Privacy and Fraud Attorney
Project Greenstar was used to monitor phone calls made on AT&T's
network between 1964 and 1970. Automated units were installed at
various locations to intercept a subset of phone calls routed through
that location and determine if there indications of an exploit being
used. If a call was determined to have been made using an exploit, the
call was recorded for further analysis.
1966 - Greenstar Wiretapping used to prosecute bookies