Dong

A device that makes a "dong" noise and once you hear the noise, every school in a kilometre radius explodes. It is otherwise used as a pedophile alarm system and all pedos will hear this alarm.

Person 1:"did you hear about that massive dong incident that killed 1000's of kids?"
Person 2:"An explosion killed 1000 kids?"
Person 1:"I heard also that someone rang a dong and all the pedos invaded his house."