I found this article Trace Mayer wrote about bitcoin in January of 2011. It's kind of an historical artifact:
I found this passage interesting:
The risk is currently very low that anyone who engages in the business of exchanging national currencies for Bitcoins within jurisdiction of US federal law will be subject to regulation as a Money Service Business.
I don't think Samourai and Tornado cash devs would agree!
Disney is not listed as a registered Money Service Business for selling Disney Dollars. Washington D.C. area businesses trade in a local currency called Potomacs to support local businesses, but nobody is registered as an MSB to exchange those. Even virtual currencies like those used in World of Warcraft or Second Life, which regularly are exchanged for national currencies, have never given rise to registration requirements. But, none of those currencies ever posed a threat to the power of the money printing press that central banks now enjoy.