Introduction: Telephone traffic analysis

[f_griffith at TITAN.SFASU.EDU]

>They track and compare the frequency of calling patterns made by the targets.
>Now they know the "calling circle" of the targets.  They expand the tracking
>pattern and start looking for cross overs.

Tom Clancy in _Clear and Present Danger_ has a description of the CIA
doing something like this to the Columbia drug cartel.