They may criminalized and that, by experience will just create more adoption and the black market, which is, huge, will just growth more and more across the world, regulation and over protective measures are one thing, but criminalizing the privacy of an asset ownership won't stand in any superior court of law in USA, I would assume that it will be destroyed in any Federal court once appealed and if it gets to the Supreme Court, which will be quite odd to me, the outcome should be obvious in favor of privacy.
Time will say...