Here’s what I think is coming:

1) force all US wallets to be registered under FBAR. Don’t worry, they’ll make it easy to do. Just hand over your tax ID and xpub.

2) release an API to check if a wallet address is registered

3) force exchanges to block all withdrawals to unregistered wallets; force software wallets to block all transfers from registered wallets to unregistered wallets; force businesses to block receipt of payments from unregistered wallets.

3) create a penalty, seizure and / or jail, for having control an unregistered wallet. If your unregistered bitcoin is transferred to a regulated entity, poof it’s gone.

Of course this won’t stop bitcoin. It’s just going to make life for Americans hell unless a few States stand up and push back. Also, countries will compete for bitcoiners so there will be places to go.