The Simpsons S15 E21 Bart-Mangled Banner

"Just a product of society that's lost its good manners."

After receiving an injection from Dr. Hibbert, Bart becomes temporarily deaf, which makes him impervious to being bullied, until he accidentally moons the American flag during a donkey basketball game, prompting everyone in town to accuse the Simpsons of being unpatriotic under the new "Government Knows Best" Act.