But they can't switch my Maples, or Krugerands... ;o)
No, but they will probably make it illegal (a class A felony_ to buy or sell with unregistered gold. Registered, taxed, and them probably turned in FDR style at some set price, maybe $1,000 New Dollars.
If you try to buck the new fiat system by using PMs for private purchases, expect to be an outlaw. Expect sting operations, snitch lines, etc.