LED street art and the 2007 Boston Bomb Scare

An electronic street sign designed for advertisement was the cause for a terror alarm in Boston in January 2007. The sign showed a led-lit version of a character of the animation series Aqua Teen Hunger Force. The device, which construction was similar to that of the LED throwies and the Night Writer by the Graffiti Research Lab, was misinterpreted by Boston Police Officers as an explosive mechanism.

Wikipedia article.