[Oberon]

Hmmm. This could get very ticklish. Technically, this means that if I borrow a silver coin from you and write you a receipt for it, I've broken the law. That's all that real money is, you know... a receipt for real currency (i.e. coin or bullion) on deposit.

[IMHO]

Our "money" or federal reserve notes, are not backed by anything resembling gold or silver. They are simply monetized debt, backed by the ability of the government to collect taxes in the future (i.e. the full faith and credit of the United States Government). Since there is no way to pay back both the monetized debt (FRNs) and the interest, the Gov't is technically bankrupt and has been since they ended the gold standard.

Aside from that, even if these people evade gov't intervention, they will run smack into Gresham's Law, which will crush them like a bug.