"No Pants Subway Ride"

This event is run by the group Improv Everywhere, and is intended to make people laugh and have an interesting New York experience. When asked, participants are not supposed to reveal the purpose, they are asked to respond with something such as, "I forgot my pants today."

Participants riding on the train Participants waiting for the train A participant removes her pants in a train car A girl's reaction as participants ride the train in the annual "No Pants Subway Ride" in New York January 13, 2007.

Taken from: China Economic Net

Why is there such interesting event in New York and Singapore don't have?