The annual ‘No Pants Subway Ride’ started way back in 2002, in New York City. It’s been 17 years since the first event and it’s still going strong.

Originally, it began with a small prank between seven guys. Now, it has grown into “an international celebration of silliness,” and dozens of cities around the world are participating every year. In its 18 years of existence, the event has had quite a colorful history.

In No Pants Subway Ride 2006, a cop arrested 8 of the 150 participants of the event. They were taken into custody, though the judge did dismiss all the charges the following month since NYC has no explicit laws about wearing your underwear in public.

The 2009 event was the first one with over 1000 participants. For the very first time, the NYC event took place during a snowstorm. Talk about cold!

The No Pants Subway Ride 2015 was conducted all over the world, but Latvian officials almost got to ban the event until the media stepped in. Tens of thousands of people participated.

This year, the participants in NYC had to face 32-degree weather in their underwear. While the event’s actual date changes from year to year, it happens every January and gets announced as early as December.