Organizers group participants by birth month as they prepare to start the 9th Annual No Pants Metro Ride, in Washington on January 10, 2009. The group Improv Everywhere organized the international event which had participants in 44 cities in 16 countries. UPI/Kevin Dietsch | License Photo

An organizer holds a rules sign prior to the 9th Annual No Pants Metro Ride, in Washington on January 10, 2009. The group Improv Everywhere organized the international event which had participants in 44 cities in 16 countries. UPI/Kevin Dietsch | License Photo

A Pantsless woman and a person dressed as a bear walk to make their train as they participates in the 9th Annual No Pants Metro Ride, in Washington on January 10, 2009. The group Improv Everywhere organized the international event which had participants in 44 cities in 16 countries. UPI/Kevin Dietsch | License Photo

A Pantsless Metro rider participates in the 9th Annual No Pants Metro Ride, in Washington on January 10, 2009. The group Improv Everywhere organized the international event which had participants in 44 cities in 16 countries. UPI/Kevin Dietsch | License Photo

Metro riders take off their pants as they participate in the 9th Annual No Pants Metro Ride, in Washington on January 10, 2009. The group Improv Everywhere organized the international event which had participants in 44 cities in 16 countries. UPI/Kevin Dietsch | License Photo

A pantsless Metro rider participates in the 9th Annual No Pants Metro Ride, in Washington on January 10, 2009. The group Improv Everywhere organized the international event which had participants in 44 cities in 16 countries. UPI/Kevin Dietsch | License Photo

Pantsless Metro riders participate in the 9th Annual No Pants Metro Ride, in Washington on January 10, 2009. The group Improv Everywhere organized the international event which had participants in 44 cities in 16 countries. UPI/Kevin Dietsch | License Photo

Pantsless Metro riders wait for a train as they participate in the 9th Annual No Pants Metro Ride, in Washington on January 10, 2009. The group Improv Everywhere organized the international event which had participants in 44 cities in 16 countries. UPI/Kevin Dietsch | License Photo

A pantsless Metro rider participates in the 9th Annual No Pants Metro Ride, in Washington on January 10, 2009. The group Improv Everywhere organized the international event which had participants in 44 cities in 16 countries. UPI/Kevin Dietsch | License Photo