How do you spend your January weekends? Some people take a Polar Bear Plunge, others ride the subway with no pants on

Improv Everywhere, YouTube

Over 4000 people in New York participated in the 13th annual No Pants Subway Ride yesterday. The event takes place in over 60 cities and 25 countries around the world.

The No Pants Subway Ride is an annual event staged by Improv Everywhere every January in New York City. The mission started as a small prank with seven guys, and has grown into an international celebration of silliness, with dozens of cities around the world participating each year. The idea behind No Pants is simple: Random passengers board a subway car at separate stops in the middle of winter without pants. The participants do not behave as if they know each other, and they all wear winter coats, hats, scarves, and gloves. The only unusual thing is their lack of pants.

Here is an overview of the history of The No Pants Subway Ride dating back to its inception in 2002. You can learn more about this history of this event and of Improv Everywhere in the new documentary feature, We Cause Scenes.