call them are a big concern. if we know they went to libya, why don't we know if they're in the u.s., and do we know their names, and how great a danger is this? >> there's lots of ways to get into syria that wouldn't necessarily in and of itself raise the red flag of concern. you could, the easiest route today is to fly into turkey and disappear for a while, come off the grid, spend as much time as you want in both syria and/or iraq or both and come back and fly out of turkey that wouldn't necessarily rise to the standard. remember, these are u.s. persons. these are u.s. citizens. that's what the challenge is, or they're british citizens or german citizens or spanish citizens. that raises a level of difficulty for u.s. intelligence services in a way we haven't seen in the numbers that they're trying to figure out who these people are and what their intentions are. that's what's so dangerous about this and why allowing them to pool up in syria, allowing them to have safe haven the size of