Here in New Mexico this is a way of life. The military checkpoints that the Border Patrol has set up everywhere routinely check for such things as radioactivity. When a chemical stress test is administered in cardiac units in Las Cruces, for instance, the patient is given a document describing the isotope used, the procedure administered, and contact information. The patient is then briefed on what to expect at the military check points. Having gone through such a test I can affirm that the monitoring system works. Alarms go off when you approaching the questioning zone - you are ordered to drive your vehicle to a segregated area - Border Patrol Agents with geiger counters surround your vehicle - if you are lucky, some idiot will babble spanish as you incessantly (as if spanish speaking and radioactivity had something to do with each other) and eventually they will clear you to return to your home. All of this so the people of Kansas and Oklahoma can feel safe - I don't care if the cowards feel safe or not.