> you are guilty of money laundering if a copy is found on your computer -- now running the Ethereum mainnet or any fork that contains it is illegal in the United States
This is well beyond the regulatory and legal powers of the U.S. Treasury and the DOJ. That is not the letter of the law with regards to money laundering, and the agency cannot invent new laws out of thin air. Nor can they blanket ban a technology or code just because they have to learn new stuff. Could Congress pass such a law? Sure, but even then, we'll go to the mats in the court and in state legislatures. Nevermind that criminalizing and demonizing a large portion of the population hurts your re-election chances.
Even torrenting, as egregious as the copyright abuse was in Pirate Bay's heyday, was never banned in such a way. Email scams from Nigeria never necessitated the shutdown of email. VPNs continue to operate.
Nevermind that similar cases with regards to cryptography have already gone to court, which ruled in favor of speech: https://www.eff.org/deeplinks/2015/04/remembering-case-estab...
The XKCD example is amusing, but fails even the most basic cross-examination. Surely officers with a court-issued warrant for probable cause of a crime should be able to inspect a person's home or things. Maybe they could find a private key written on a post-it note somewhere in the person's home. That's all fair and good, and no one is arguing against that. Clearly, it's not very scalable, nor should it be. We operate under the presumption of innocence in free societies.
We all have a problem with illegal, abusive, mass surveillance. It is a violation of human liberty and a disturbing trend that has to be pushed against to prevent a full-on dystopian, authoritarian hellscape where you don't even have paper cash as an outlet from the panopticon. To avoid that future outcome, to preserve the freedom of your children, you have to fight for privacy and transactional liberty. My ancestors were willing to bleed and die for liberty. Some of us still are, today. Never wake a sleeping lion, indeed.