I wonder if the terrorists are dumb enough to use a weapon that they know is being screened for. "Here I am, catch me before I kill again". Well, actually, if they didn't have handlers, they might just do it. But even the guy who stuff the explosive in his skivvies had had talks with the imam in Yemen first. So there's a better than even chance SOMEONE is going to use intelligence in choosing the bomb material. The shahid doesn't have to have brains, and blowing up an educated brain is a huge waste for them.