The number of times I pull up behind some POS at a stoplight... I have this fantasy of rigging up a high power laser focused in at about 10 feet where I can just burn a message into their paint.
It comes from "molon labe" (which you'll also sometimes see) which was what the Spartans said when told to lay down their arms or face certain defeat by the Persians at thermopylae. Spoiler: they came and took them.