2007 Boston Mooninite panic

On the morning of January 31, 2007, the Boston Police Department and the Boston Fire Department mistakenly identified battery-powered LED placards depicting the Mooninites, characters from the Adult Swim animated television series Aqua Teen Hunger Force, as improvised explosive devices (IEDs), leading to a massive panic. Placed throughout the U.S city of Boston, Massachusetts, and the surrounding cities of Cambridge and Somerville by Peter "Zebbler" Berdovsky and Sean Stevens, these devices were part of a nationwide guerrilla marketing advertising campaign for Aqua Teen Hunger Force Colon Movie Film for Theaters.

Source: Wikipedia — 2007 Boston Mooninite panic (CC BY-SA 4.0)