Perhaps a bum detector might be more practical.
someone had cut some palm leaves an made a bed there.
the effort would be better spent finding and dealing with what causes people to want to build a bomb?
They are often cut off from society, believing they are the only ones right, no one believes them, so they take drastic measures to make their point
people would have to be responsible for monitoring the negative actions of other people and thus actually have to interact and possibly do something when they find out someone is planning to do something bad