training. they may go overseas because they want to help the fighters. when the individuals come back from pakistan, afghanistan, yemen, somalia, chechnya, russia, that's a point that deserves more scrutiny, to find out what did the individuals do overseas. otherwise you may have a boston event. times square bombing. 2010. individual goes to pakistan. lost track on the radar. comes back to times square in a vehicle to deliver an attack. >> it's much easier to do it if he's not a citizen. if he's not a citizen you have much more control over his travels. much more control over his ability to leave the country, his ability to return to the country. he has far fewer rights when it comes to being surveilled abroad. in the country he still has rights. you don't want to overdo the surveillance. there's a lot more that could have been done. >> is it plausible that these two brothers con conducted all