Laws are how you prevent this.
Can you imagine the Massachusetts Steamship Authority paying in cocaine?
Why would paying in Bitcoin be any different?
Bitcoin is parroted largely by a bunch of libertarian speculative grifters that think they're above the authority of our government to manage the monetary supply. They want to soak up all the advantages of building and controlling an economy.
If you look through the covers, it's all speculation and hype. There's noting "decentralized" or "democratic" about it. Bitcoiners are fine with letting social services and the underserved slip through the cracks as long as they get their reward that they feel they earned.
The US is a democracy, and theoretically it helps people of all backgrounds and socioeconomic statuses. It might not be evenly distributed, but at least we can toss out the bad players. Bitcoin is not a democracy. It rewards the Ponzi schemers at the top and leaves everyone else out to dry.
And now look at what it's gotten us -- unprecedented crime from across international boarders that we can't stop. All brought to you by the remarkable "governmentless decentralization".
Just wait until the kidnappings start. Or the murders for hire.
Fucking good for nothing bitcoin. The world was better before it existed.
Are you seriously using the war on drugs as an example of a successful policy? Drugs are easier to get and more numerous than ever, even though we have these magical laws in place for decades.
What are you basing this on?
From what I've read it seems its only the stupidest of criminals who are using exchanges like Coinbase to cash out, because that's the easiest way to get caught.
The main avenue would be by getting rid of the sanctioned on/off ramps for crypto (that is, crypto exchanges), leaving only the illegal on/off ramps which I'm sure exist.
This obviously wouldn't stop everybody, but it would certainly be a deterrent for all but the most motivated and well-connected of buyers. At that point, exchanging a large amount of crypto would be similar to laundering a large sum of dirty money; possible, but not trivial and certainly not an "easy out" for a major corporation experiencing a ransomware attack.