Watch 4,000 Strangers Drench Each Other With Water Guns [VIDEO]

Improv Everywhere's MP3 experiment is a public participatory event that's a mix of scavenger hunt and flash mob.

Everyone downloads an original MP3, then meets at a specific location and acts casual until it’s time to push play — followed by 45 minutes of syncronized, hilarious antics that leave unsuspecting visitors simultaneously confused and entertained.

This year, there were 4,000 participants, 300 of whom didn't even make it to the meeting place -- Governor's Island in New York City -- because too many people were trying to get there. Instead, they followed instructions in Battery Park.

Watch what happens when two armies of thousands go head-to-head in the most epic water gun fight.

[nggallery id=6527]