South Park: Season 4, Episode 16

4 - 16: The Wacky Molestation Adventure

Kyle's parents forbid him to go to a concert, so on Cartman's advice he calls the police and tells them his parents molested him. The other kids notice Kyle enjoying the freedom he has with his parents in jail, so they all do the same. Soon, the adults are all in jail and the town is controlled by children - something that is very spooky to a couple whose car breaks down in South Park.