The first thing you do is shut off the supply. When you have a water pipe break in the basement, you shut off the water and then address the water damage. I see no great urgency in rounding up the people already here. Employer sanctions will force many to go home and we can let many of the others fade away due to benign neglect. And if we have more state and local enforcement personnel with 287 [g] authority, it will have a multiplier effect on deportation.