[acdha]

It’s trivial to require all businesses not to touch transactions involving a list of addresses. Once that happens, all these games fall apart because trying to obscure the identity means that people will only participate in them if they intend to break the law and after the first busts they’ll learn that it’s a bad idea to publish that intention to a public ledger.

[gruez]

You can't say "don't touch coins from these addresses" because it would be trivial to DoS people by sending dust from a blacklisted address to other people's wallets.

[acdha]

If they sent more than infinitesimal amounts, it’s unsustainable; if they don’t, it’s easily filtered — and that’s assuming that they didn’t just direct you to send the amount to some dump address if you wanted to disavow it. Simply telling a few large exchanges to do that automatically would take care of the majority of users.

[throw99c]

You have to be loaded to consider DoSing with current transaction fees anywhere near practical.

And it's not like the government couldn't fine the businesses equal to say, 1.5x the amount transferred from the blacklisted address.