Correct me if I'm wrong, but didn't the U.S. Government outlaw the private ownership of gold for about 40 years, from 1933 to 1972? (That's not including the so-called rare or collectible gold coins, of course.)
My problem with this gold/fiat currency debate is exactly that: the government can (and will) screw with both entities to their own advantage. Buyer beware....
"Uncle Joe's" buddy Roosevelt stole the gold from the American people, or those who weren't smart enough to stash it.
Government cannot change the value of gold. It can prevent citizens from legally holding it. It can inflate and deflate the currency but gold will retain its value against other commodities. The government hinders and damages the economy whenever it tries to manipulate the value of gold but only succeeds in making it more sought after because of its unchangeable nature.