If they can't get in here, then that chance is remote.
All of you folks wriging your hands over "safety" should be marching on something to have the borders clamped off. Then you can be "safe" without having someone touch your cherry flavored K-Y to avail yourself of public transit.
And really, wouldn't that be preferable?
If you get nothing else from this discussion, please get this:
THEY'RE ALREADY HERE...