A lame excuse for a cop to pull you over, and only dangerous if done improperly, a rolling stop is when you don't come to a complete stop at a stop sign. This includes slowing down to .0000002 mph to look both ways in an unoccupied industrial district. Basically if your wheel doesn't stop moving, you've done a "rolling stop" in the eyes of the law.
Cop: Do you know why I pulled you over?
Victim: I was hoping you could tell me, and obviously I don't know why you pulled me over otherwise I wouldn'tve done it in front of you.
Cop: You did a rolling stop back there.
Victim: ...back there at my driveway on the cul-de-sac?
Cop: I don't speak French.