how powerful are they? why do they do these things? >> they've been around in different guises for several years now. elements of the pakistani military and the pakistani sky agency have encouraged them, have given them -- have supplied them. in the last two or three years, their wrath has been turned at the pakistani state. their grievances are quite complex. there are tribal grievances, ethnic grievances. they have this view of the world that we are now familiar with from islamic terrorist groups around the world, they want to return to this idea of pure islamic state as it existed during the time of the prophet muhammad 1,400 years ago. their views about modern education, about women and girls are very retrograde. and they have demonstrated over and over again they have no qualms about targeting children,