We knew this a long time ago. Just like Diamonds.
I remember a few years ago I read a trade article about avoiding investing in gold certificates. They sell more paper certificates than the gold that's available. Sounds familiar doesn't it. Being able to buy more stocks than available for the short investing.
The article also advised you to check the numbers on those gold certificates and see if there is an actual brick with those numbers on it to verify.
Forgot to add, there's going to be many people who are going to get screwed when the shit hits the fan and they put a call on those gold certificates.