they come from people who want to be homegrown extremists. it doesn't lomatter if you don' succeed. put forth the best of your efforts and you'll become a hero, regardless of whether or not the bomb goes off. if you try to commit an act of violence, you will become a hero in our minds. you will become a martyr. there is some sense not that you have to carry out a successful terrorist attack, make the effort. scare the american public. terrify people that want to get on airplanes. that's the idea. to spread fear. and you don't need 19 people to do that. you can just get one or two people spread across large areas or distances. >> you describe it that way, and you realize what a challenge this is to keep america safe. one whack job with a bomb in his backpack. how many people are walking around new york city? >> it's the proverbial needle in a haystack. al qaeda the pakistani taliban, they all know thisp and they're pointing to examples like faisal