There are reports on the web that some very sophisticated counterfeiters have constructed thousands of gold-plated tungsten bars which look, weigh, and measure the same as an ordinary 400 oz gold bullion bars. In other words, the unscrupulous and proficient counterfeiter could convert $270 of tungsten and a few ounces of gold into a bar which cannot be easily distinguished from the approximately $480,000 real thing.
But that's actually a lot of work to only make a few billion. What would be better is if you could make tens or hundreds of billions of dollars like Goldman Sachs and Magnatar did when they (1) created super-risky collateralized debt obligations (CDO) from sub-prime mortgages and then (2) bought credit default swaps which paid out many times their portion of the CDO when the CDO defaulted. How slick is that? No precision manufacturing of physical products or inventory management to worry about!
But who has time to scrap over a few billion when there are trillions to be made selling air? Imagine how much money you could make if (1) you could simply make "credits" from nothing, (2) sell them to people for the right to create/emit carbon dioxide, and then (3) charge an overhead fee when people sell those excess credits to one another? That's exactly what will happen when the "cap and trade" bill passes. And of course, none other than Goldman Sachs is there to reap the profits...
I think the gold-plated tungsten peddlers have the most honest business going of the three.