I'm thinking a possible way might be co-ordinated approach with a number of countries: USA, Canada, Europe, Japan, Australia, NZ etc all signing up to confiscate gold from their citizens.(Our govt is stupid enough to do it). This would in effect quell some of the demand which is what the banksters want. I doubt China, Russia, Mid East, India, Africa would sign up for it, but perhaps it doesn't matter.
I suspect they'd confiscate bullion & coins, but couldn't confiscate jewellry or gold shares (ie you can buy the ETF but you can't get bullion).
It wouldn't be easy to do. Some people would fall through the net by holding gold in some remote island that didn't sign up to the confiscation (ie rich people). Others would simply leave the USA and go and live a non-confiscation country.
The difficult bit with this scenario is that silver would become the metal of choice. They'd probably have to ban that as well as platinum, rhodium and any other rare earth metal.