18 USC § 486:
"Whoever, except as authorized by law, makes or utters or passes, or attempts to utter or pass, any coins of gold or silver or other metal, or alloys of metals, intended for use as current money, whether in the resemblance of coins of the United States or of foreign countries, or of original design, shall be fined under this title or imprisoned not more than five years, or both."
Ah... well sort of... 11 States the last time I checked have re-instituted their right to use Gold as a currency starting with Utah, IIRC. Although those coins, have been duly produced by a Federal Government. Do so, basically allows people to buy gold coins without paying a tax. So you don't get taxed for buying currency.
But under your premise, AMPEX couldn't operate. They seem to have been doing so for a long time.
Casa Coins are A)Either an metal (silver or gold) or B) a token. However the token is pretty much worthless just like the Dabloons from Mardi Gras. Their only value is the private key on them, which could be on anything. So if the government really causes a fuss about the tokens, he could sell Pet Rocks with BTC on them. Or Sea Shells...
