Around 100 people braved the cold weather to ride London's subway in their
pants on January 10 as part of the annual No Trousers Tube Ride: London,
according to the Daily Mail. Started by a group called Improv Everywhere in New
York in 2002, this annual event has two requirements for taking part in: a
willingness to take trousers off on the Tube and the ability to keep a straight
face。