Two words: Ft. Dix
And how do you know they haven't? How do you know they won't today, or tomorrow, or next week?
Gamble with your own life, pal.
They are coming here on legal visas, or EU and Canadian passports that do not require a visa, and some are already here as US citizens or legal permanent resident.
"Don't worry. Most of the bad people who want to kill you are already here, so there's absolutely no need to lock the door to keep any more of them out."
Idiocy. Sheer idiocy.
L