If it comes to a ban (unlikely) I think they want us to voluntarily turn them in like they did in Britain and Australia. IMO we will do as Canadians did only more so. We just won't comply. The fewer who do comply the less they can do about it. The Canadians essentially Cloward & Pivened their registry system. They forced their government to spend the program out of existence.
I don't know what other alternative they have.