Am I being naive here, or is the idea of evil-doers trying to cross the border slightly, ummm, outdated? Couldn't they just fly in or something? I mean, they aren't going to come into the country with their pockets stuffed full of C-4, and weilding AK-47's are they?
If they intend to commit an act of violence, they'll find some way in. Border security is barely in the equation.