Improv Everywhere is a New York City-based prank collective
that causes scenes of chaos and joy in public places. Created in August of 2001
by Charlie Todd, Improv Everywhere has executed over 100 missions involving
tens of thousands of undercover agents.
For their latest stunt, over 3,500 people downloaded an MP3
file and pressed play simultaneously. The event began at sunset in two starting
points by the Hudson River in New York City. The masses converged on Nelson
Rockefeller Park as twilight ended and participated in a series of synchronized
activities involving flashlights, camera flashes, glow sticks, and masks.
Their “Ghostbusters” stunt inside the New York Public Library
is the stuff of legend: http://www.youtube.com/watch?v=wKB7zfopiUA