It's mid-January, and that can only mean one thing: time to drop trou in NYC. On Sunday, for the 12th annual No Pants Subway Ride, over 4,000 riders took off their pants in the 52-degree weather and hopped on the subway. The annual ride is organized by Improv Everywhere, a NYC based prank group that "causes scenes of chaos and joy in public places." The movement has spread around the world, and this year, thousands of bare-bottomed pranksters participated in more than 25 countries, including China, Australia, and Mexico. Check out some of the most ridiculous scenes from the subway ride in NYC this weekend.