MF Global used to be known as Man Financial, and it had a reasonably good reputation. It did a humdrum business placing commodities trades for fund managers as well as farmers, grain dealers and others whose livelihoods depend on the vagaries of commodity prices.
No other facet of American business is more corrupt, more intoxicated with illegality, more weakly regulated, and has a greater impact on poor and working people than debt collectors; not credit card companies or subprime mortgages, not even payday lenders.
Oil futures were originally created to give heating oil dealers, gas retailers, aviation companies and other businesses a method of hedging against adverse price changes. Instead, they've become just another Wall Street plaything.