Hell, they probably have the technology to do so without the dude even being able to make a call other than 911.
I may be mistaken, but I have been led to believe that all cell phones (possibly mandated by law) were required the ability to make emergency calls to 911 regardless of service status. I know with all the phones I've had, with the SIM card removed (no SIM, no authentication, no service, no calls) allows emergency calls to 911 (in fact, will ignore all key presses other than the sequence 9,1,1, TALK).
Take care of the luxuries and the necessities will take care of themselves. -- Lazarus Long