Another 24 people were killed in Pakistan today when U.S. drones fired at some houses in the Kurram tribal region.

One wonders how the U.S. gets information about alleged Taliban meetings it fires on. I do not believe that it has significant human intelligence, i.e. spies, on the ground. The video information it gets from observation drones is also not good enough to go after specific people. But there is a third leg of information gathering that I always suspected to be involved – signal intelligence from mobile phone location data.

Indeed at the end of an NYT piece today we learn:

In carrying out missile strikes, the C.I.A. has steadily developed its own network of sources in the tribal areas, and combined with improved information-sharing with Pakistan’s main intelligence agency in recent months, as well as some technical advances like installing more mobile towers to intercept cellphone calls, the agency has been getting much better intelligence on its drone targets than it did just a few months ago, officials said.

Those mobile towers may not be really towers but simply other drones that carry mobile phone base station equipment and catch the movement of cell-phones and their attached human beings:

An IMSI-catcher is a device for forcing the transmission of the International Mobile Subscriber Identity (IMSI) and intercepting GSM mobile phone calls.
..
Every mobile phone has the requirement to optimize the reception. If there are more than one base station of the subscribed network operator accessible, it will always choose the one with the strongest signal. An IMSI-catcher masquerades as a base station and causes every mobile phone of the simulated network operator within a defined radius to log in.

Using one or more mobile and even air-mobile IMSI catchers the CIA can over time register the movement of all mobile phones in an area. If a phone crosses the border from Afghanistan to Pakistan and meets another mobile phone that has been used to make a call to Yemen and another that called some suspicious number elsewhere that would be a possible target.

Of course over time Darwin's law will set in and the smart fighters that avoid to carry or getting near a cell phone will survive and not be detectable by such means. Unfortunately that will be unlikely to stop the CIA or Air Force to blow up people. Everyone needs to make the body-count numbers. As more the Mujaheddin learn, more innocent people will be killed by their adversaries. That will work well for the Mujaheddin cause.