Abridgement of legal rights is very real.
It has nothing to do with whether or not fundamentalist nuts have violence in mind for Western civilization. The point is, freedom dies not if it's attacked from without, but only when it's abandoned from within.
If we give up our liberty because the terrorists have scared us, they have won, and without blowing up anything else. They cannot conquer us. Fear does that.
We have started to parse out who deserves liberty and the protection of law. Aliens, apparently, don't deserve it. Whether or not anyone has been dragged off is beside the point.
Who's next? When fear runs the show, after the present target gets cold, there always has to be another one. Otherwise, we may cease to be afraid, and that's no good!