Thousands Go Bare in Worldwide No Pants Subway Ride

Camille Bautista

New York City

Photo courtesy of Instagram, slepka

Click here to view this gallery.

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Commuters in subway stations around the globe were turned into peeping Toms on Sunday, as many unwittingly faced their fellow travelers' underclothes.

Straphangers got an eyeful during the 12th annual No Pants Subway Ride, a prank started in 2002 by Improv Everywhere. The New York City-based group calls themselves a "prank collective that causes scenes of chaos and joy in public places." And what could possibly bring more joy than strangers in their underwear?

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Thousands participated in more than 25 countries, including China, Australia and Mexico. In Seattle, pranksters braved 37-degree weather sans pants.

There are only two requirements: Take 'em off and keep a straight face. No thongs or other offensive underwear are allowed, but everything else is fair game.

Participants are organized into groups and assigned a specific train car, but can't speak to one another. The first No Pants Subway Ride had just seven men and a pants peddler who later came through the car with a duffle bag. This year, NYC had more than 4,000 bare-bottomed pranksters.

Check out this year's video and take a peek at our gallery, above, of pants-less people around the world.

Thumbnail image via Timothy A. Clary/AFP/Getty Images

This story originally published on Mashable here.