I was just thinking that if businesses and organizations start requiring papers, we could employ flash mobs like with the masks. Large groups go in without their papers and just shop or enjoy the event or whatever.

Another strategy to be employed concurrent would be to make it personally difficult for anyone who enforces such a law. I don't yet know the best way to do that, but individuals need to know that of they enforce unconstitutional mandates, they will be personally held accountable.