I'm having this discussion with a friend on Facebook. Please try to think of a situation or scenario where running your engine while pumping gas, will cause a fire. The car running must provide the source of ignition, anything can happen to the car, or to the pump, or the owner can be a dumbass somehow, but your proposed scenario can only happen because the car was running. After creating the scenario, ask yourself, "Could this have happened with the car off"? I'm coming up pretty empty handed.