This is a true story according to a recent issue of Road and Track Magazine:

When a man attempted to siphon gasoline from a motorhome parked on a Seattle street, he got much more than he bargained for. Police arrived at the scene to find an ill man curled up next to a motorhome near spilled sewage. A police spokesman said that the man admitted to trying to steal gasoline and plugged his hose into the motorhome`s sewage tank by mistake.

The owner of the vehicle declined to press charges, saying that it was the best laugh he'd ever had.
[heavy]