Guerrillas and terrorists are not fools. They are aware they may be under surveillance, and take what they hope are appropriate counter-measures. They are unlikely, for example, to make calls from inside a safe house in which they are living. Instead, they typically make calls from roughly spaced out nearby locations, taking care not to call too often from the same spot. They hope, thereby, that if their activity is being monitored, it will appear random and therefore meaningless.
Spacing things out like this is, in mathematical fact, anything but random: that, in itself, is suspicious. But true randomness would also be odd. As Ian Laverty, the boss of ECRI, a geoprofiling-software firm in Vancouver, observes, innocent phone calls have geographical patterns, because people have routines. Those who take steps to elude the authorities thus often end up unwittingly creating a profile of where their home base is—a profile that a piece of ECRI’s software called Rigel Analyst can spot. This software is used by more than 90 intelligence agencies around the world. Its applications include searching for Taliban rocket caches in Afghanistan.
Geoprofiling is thus already an important counter-insurgency tool…according to a geoprofiler in Denmark’s intelligence apparatus who prefers to remain anonymous. This operative uses geoprofiling software called ArcGIS that analyses Global Positioning System (GPS) data provided unwittingly by insurgents’ growing use of smartphones and other gadgets that are equipped, by default, with GPS kit. For example, simply right-clicking on propaganda images posted online often obtains a GPS “geocode” that reveals where the picture was taken.
Excerpts from Counter-Terrorism, Shrinking the Haystack, Jan. 16, 2016, at 86