They will retreat into the shadows, they must be dragged kicking and screaming into the light to be exposed and held accountable or they will return - dirtier and meaner than before.
As far as I am concerned they should be included in the groups being deported. Revoke their citizenship and send them to some third world hell hole.
“Kryptonizing” the global swamp won’t be easy but as one U.S. President boldly said, “We choose to go to the Moon in this decade and do the other things, not because they are easy, but because they are hard”, and there is much more at stake now than there was then!