I agree that it can be done, but at what cost to the american taxpayer? In the long run, it would seem to make more sense to just get them legal, and have them start paying taxes. This would mean more tax money coming in, instead of more tax money going out.
My biggest issue with this is the ones, legal or not, that come to america and fly the flag of their own country instead of the american flag. If your country is so damn great that you feel the need to have its flag on everything you own, then what the hell did you come here for in the first place???