Even worse than an alcohol ban, as alcohol has a conspicuous 'meat space' presence and people who have recently participated in alcohol related activities are often rather easy to pick out.

His demands that regulators prevent Americans from being left 'holding the ball' if/when bitcoin collapses could reasonably be interpreted as a call for a ban on merely possessing bitcoins (not just transfering/selling/mining). If that were to happen (which is unlikely, but seems to be what this asshat wants), having a brainwallet could be considered a "thoughcrime" in the literal, non-hyperbolic sense.

It gets absurd. "Owning bitcoin" is just linguistic sugar for having knowledge of a private key that corresponds to a public key that hashes to a bitcoin address that holds bitcoin. It's just a 256-bit number. In essense, every single private key represented on the blockchain becomes an illegal number (https://en.wikipedia.org/wiki/Illegal_number), and not just illegal to publish, but illegal to store and even illegal to think about (aka know about).