Leaving names out of this post..I was informed WAY back in the 70's that we had more than Illegal Mexicans coming across the border and was told that if that's all we are worried about then America is in for a great awakening. Now remember I said I was informed about this in the 70's. The person who told me this is still working in a department that monitors this type of activity.
One can only imagine the things we don't hear about in the world. Think of all of the possibilities the FBI or Homeland actually stop and never make it on the local news. You can't walk down the street and wonder about the person walking towards you, is he just a normal guy like you or a radical.