People resort to the black market for all sorts of stolen goods: mobile phones, watches, cars, babies. But used cooking oil? According to the Washington Post, that's a thing too.
Thieves are now moving into the green market by stealing used cooking oil from the back of restaurants. They sell the sludge to recyclers, who then process it into biodiesel. The oil can go for as much as $US4 per 3.7L on the down low.
Since this is a pretty new criminal enterprise, police aren't entirely sure what to do with the perps -- or how to stop the theft from happening. In some states it's a misdemeanour. Meanwhile in Virginia, two men caught grease-lifting were charged with grand larceny. Serves you right for those sticky, er, slippery fingers.