"You can't ban dollars, you'd have to make governments illegal!" is the all-too-frequent reply to anarchocapitalists who advocate for the separation of state and economy. And it's true, more-or-less; while we can prosecute corrupt politicians, there's little we can do to get rid of political structures that are inherently problematic.
What I don't get, though, is why any upstanding citizen would want to help them out.
Like any government-backed money instrument, dollars are created through a system that starts with federalized debt; the usual economic cycle is that the treasury issues a note (realistically an unbounded proposition in spite of 'debt ceilings), and exchanges them with a rich person or institutional investor seeking a percentage return. This note is then exchanged with the Federal Reserve bank, which in turn instructs the treasury to print up dollar bills to satisfy this debt (with interest).
The one unique twist is that, being purely a political instrument, there is no physical limit to this process and because overprinting money devalues savings of the poor (and typically only bankers and the rich have impactful access to the yield-bearing interest) the only thing limiting total economic collapse is how effectively the government can hoodwink the populace into thinking that spending is good for them - so the poor are thrown peanuts in terms of token social programmes while other rich people like contractors and so forth (most recently big pharma and healthcare sector) really get the mother lode in spending (and bankers and fund managers make away with the interest)... But in the united states, a full 50% or so percent goes to the "defense" department and the "defense industry" (read: "war" department and "warmaking industry").
Dollars are, as Smedley Butler described, are, a currency designed to facilitate the military industrial complex. When a guy walks into a place of business and uses cash (or really any dollar-backed financial instrument, such as a credit card or checks), ultimately, 50% of the debt that was used to bring that dollar into existence went to finance a sprawling imperial organization with thugs stationed in 180-odd countries around the world, has invaded no less than two countries in the last decade and is responsible for bullyish diplomatic (and sometimes underhanded) tactics for over a century.
And yet we celebrate when a business starts accepting dollars, a currency that comes into existence supporting a questionable military. We create companies whose mission is helping them trade this dirty money for clean. We ask reputable sites to legitimize it by treating it as just one more money transfer service, like accepting a new credit card type.
It's time for those of us who believe in peace to put a stop to this. I don't suggest making dollars illegal - enforcing such a ban would require truly scary violations of liberty. But what we can do is establish a social norm of treating dollars like the warmongering tokens they are. Don't accept them in payment, and look twice at a seller who accepts them - if you can find a similar business that takes, say bitcoins, buy from them instead.
It won't stop dollars completely - an financial instrument that owes a full 50% of its existence to the US military industrial complex. But if decent people don't accept dollars, it means these thugs and worse will have to finance their morally questionable acts by asking us directly, which allows us to at least have some moral oversight, cutting in to their warmaking ability. And that, by the simple rules of democratic principles that supposedly the US believes in, means that people will feel the cost of war by direct taxation, and fewer politicians will choose to wage wars.