Crowds of excited commuters were seen stripped of their pants, and some down to their underwear, to commemorate the annual "No Pants Subway Ride" in New York City, U.S., January 12. /Xinhua Photo

The "No Pants Subway Ride" is an annual event started in 2002 by comedy performance art group Improv Everywhere. /Xinhua Photo

According to Improv Everywhere, the fun event "has grown into an international celebration of silliness, with dozens of cities around the world participating each year," including Phoenix, Philadelphia, Boston, and London. /Xinhua Photo

Reasons for attending the event varies from person to person. Many said it shows a sense of community and offers a carefree delight. And others were just out to have fun. /Xinhua Photo