I want to say at that outset that I do not own an All-Terrain Vehicle (ATV), and as far as I can remember I have never even riden one. I remember that some neighbors of mine growing up had one, and it looked like fun, but my parents wouldn't let me anywhere near it. So, it is not out of any deep personal affection for the ATV that I keep urging that, before law-enforcement officials stop and question ATV driver, they need to have a reason. The Fourth Amendment says that in order to be lawful, a search or a seizure must be reasonable, and in most instances, the complete lack of a reason means the stop is not reasonable. This is not too difficult.