The Telegraph in London was the first to report that Syrian government forces could have "locked on" to satellite phone signals to launch the rocket attacks that killed journalists Marie Colvin and Rémi Ochlik, as well as many Syrian civilians, besides wounding dozens more including two more international journalists. Working out of a makeshift press center in Homs, foreign correspondents and local citizen journalists alike have been using satellite phones to send images of attacks on civilians around the world.
Without evidence, it is impossible to know whether Syrian forces tracked the journalists' satellite signals to target the attack. And one should keep in mind that the building being used as a makeshift press center in Homs may have been known to many people in the city.
Yet the consensus among technologists devoted to Internet freedom is clear.
"Satellite phone tracking is not only possible, it's widely used by military and security services," one human rights-oriented technologist with experience training citizen activists in Syria told CPJ.
Jacob Appelbaum, a technologist associated with the Internet circumvention tool popular among human rights activists known as Tor, was among the first to warn journalists via @ioerror on Twitter: "No matter what - unless you 'know' otherwise, your Satellite phone almost certainly discloses your exact GPS location in an insecure manner."
There are at least three ways to track a satellite phone. Tracking radio frequency emissions is one. "It is relatively simple to receive this signal for a trained technician, " reports SaferMobile, a U.S.-based nonprofit group dedicated to helping activists, human rights defenders and journalists share information, in a blog this week pegged to the above attack.
Using commercially available tracking devices is another. "There is ample technology already on the market for doing so," the Electronic Frontier Foundation, another, San Francisco-based nonprofit organization, wrote in a blog yesterday. Companies including the Polish firm TS2 sell monitoring equipment to track different models of satellite phones. The Italian firm Area SpA sold surveillance equipment to Syria last year in advance of the current crackdown, according to Bloomberg News and EFF.
Finally, satellite phones can be tracked through their own built-in GPS devices or weak encryption protocols. "It is very likely that the GPS location data is transmitted by the sat phone in the clear," reports Safer Mobile. "Additionally and important as a side note -- aside from revealing your location with a sat phone -- the encryption used by commercial satellite telephone systems has been recently cracked."
So what are journalists and citizen journalists to do? In an environment where normal Internet access is either shut down or severely restricted, satellite phones remain a key way to transmit and report information. For now, alternatives such as amateur radio links or -- as this report from Syria suggests, using carrier pigeons -- are largely infeasible replacements.
Technologists with experience operating in hostile environments tell CPJ that one should use a satellite phone in such situations only with strict radio discipline:
-Avoid using a satellite phone (or any radio frequency based device) from the same position more than once.
-Avoid using a satellite phone or similar device from a location that cannot be easily evacuated in case of attack.
-Keep the maximum length of any transmission to 10 minutes at most, then cease transmitting and change location as soon as possible.
-Avoid having multiple parties transmit from the same location, i.e. a central media center may be too dangerous to operate in a place like Homs, Syria.