People in New York City participate in the "No Pants Subway Ride" on Sunday, January 10. The annual event, started in 2002 by Improv Everywhere in New York, has spread to other cities across the globe. People ride the subway dressed in normal winter clothes without pants -- all while keeping a straight face.
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People ride without pants on the Jerusalem light train.
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A man rides the Metro in Washington.
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A commuter takes a photo of participants traveling on a London underground train.
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Two men clad in colorful underwear walk up subway steps in New York.
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Passengers depart a train in Prague, Czech Republic.
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Men without pants wait for a train at a subway station in Hamburg, Germany.
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Two men wait for a train in their underwear in Warsaw, Poland.
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Los Angeles participants ride a Metro train.
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Passengers ride down escalators in Prague.
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People wait for a train in Washington.
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Riders take part in the event in Bucharest, Romania.