That's sort of the point. There needs to be built-in tracking and registration of all of them. The fact that they can be bypassed is a national security flaw. It should be hard-wired and tracked.
For very little in cost, time and knowledge one can build a short range GPS jammer that will block the GPS signal from getting to the phone.
What you want will only track honest people who, as a rule, don't blow things up.