Notice anything unusual on your Sunday commute? Thousands of people around the globe public rode transit without wearing any pants (trousers).
Those people were celebrating the annual No Pants Subway Ride, which was started in 2002 by the comedy group Improv Everywhere in New York. The event is marked by people getting onto trains wearing all their winter gear, but only their underwear on the bottom.
According to Improv Everywhere, the event started as a small prank and “has grown into an international celebration of silliness”. They explain that the goal is that people randomly board the subway at different stops without wearing pants and behave as though they do not know each other.