Yeah. When I was in J-school, I covered a court case where a man was convicted of DUI when the cops found him asleep in the back seat of a car with the engine running. He knew he was too drunk to drive and decided to sleep it off in the back. It was a cold winter night so he turned on the engine to run the heater.

He got convicted because being inside the vehicle with the engine running met the definition of "operating" it, and nobody wanted to start down that slippery slope.