[math-fun] New party trick

Math homework in Afghanistan: what is the probability that each (deranged) terrorist _doesn't_ get his own SIM card back ? https://firstlook.org/theintercept/article/2014/02/10/the-nsas-secret-role/ ... Some top Taliban leaders, knowing of the NSA’s targeting method, have purposely and randomly distributed SIM cards among their units in order to elude their trackers. “They would do things like go to meetings, take all their SIM cards out, put them in a bag, mix them up, and everybody gets a different SIM card when they leave,” the former drone operator says. “That’s how they confuse us.” As a result, even when the agency correctly identifies and targets a SIM card belonging to a terror suspect, the phone may actually be carried by someone else, who is then killed in a strike. According to the former drone operator, the geolocation cells at the NSA that run the tracking program – known as Geo Cell –sometimes facilitate strikes without knowing whether the individual in possession of a tracked cell phone or SIM card is in fact the intended target of the strike. “Once the bomb lands or a night raid happens, you know that phone is there,” he says. “But we don’t know who’s behind it, who’s holding it. It’s of course assumed that the phone belongs to a human being who is nefarious and considered an ‘unlawful enemy combatant.’ This is where it gets very shady.” ...