Did you encounter pants-less subway riders Sunday? If so, you fell victim to Improv Everywhere's 10th Annual No Pants Subway Ride. Sunday afternoon, at 3 p.m., the improvisational "flash mob" group met in various locations in New York City to receive their train assignments, and then embarked on a mostly pants-less journey to Union Square.

Organizers estimated about 3,500 subway riders went without pants on a day when the high temperature was 32 degrees, with wind gusts upwards of 40 miles per hour. There were also No Pants rides in 50 other cities around the world in 24 countries! The requirements for participation? Be willing to take your pants off on the subway, and "able to keep a straight face about it." The group even asked the media to be pants-less should they attend.

In a post on their website, IE gave an in depth overview of expected conduct. Participants were to pretend other pants-less subway riders, were strangers and wear tasteful underwear. Improv Everywhere suggested more modest folk wear two pairs of undies, and those considering wearing fundies (We thought we made that up, but apparently, such a thing exists!) keep it to things not obviously meant to draw attention. And above all, act normal!

The “official” video should be ready in a week. We expect it will look a lot like the one from last year because, you know, people who don't wear pants pretty much all look the same ...