While I have a hard time believing that anyone is buying these things thinking that they’re the same as U.S. minted currency, I understand why the feds are going after them considering some of their marketing as posted on this thread.
They’re right that it’s “legal” and “constitutional” in the same sense that I can “legally” and “constitutionally” trade you a baseball card for a pudding cup. But calling it things like “currency” and saying it can be “circulated” is probably over the line.