If they're only innocent students, why won't they turn themselves in. They have to know folks are looking for them.
If they're here to "work" why didn't they spend a month learning English and living for free to acclimate themselves to the country before going illegal?
If they're here as students why didn't they call home when they got "lost" And why did the one in Chicago not take the direct Minneapolis - Chicago flight?
My bet they are terrorists but a few were ordered to turn themselves in when the news broke to let the more important ones move freely.