By . Steve Nolan and Thomas Durante . PUBLISHED: . 21:22 EST, 13 January 2013 . | . UPDATED: . 23:18 EST, 13 January 2013 . Bare-legged riders around the globe braved the winter weather and some stares from fellow commuters on Sunday for the No Pants Subway Ride - an annual celebration of freedom, subways - and skivvies. After events in cities like London and Madrid, North America followed suit, donning just their briefs and boxers in cities like New York, Boston, Philadelphia and Mexico City. It started off as a prank by comedy group Improv Everywhere that bemused a few embarrassed commuters but has since grown into a global phenomenon. Scroll down for video . Naked ambition: Some New York City riders ditched their shirts as well as pants during the annual event . Conspirators: A group of pants-less tube riders go about their business on the London Underground in celebration of the city's No Trousers Tube Ride 2013 . Forgetting something? Commuters line up on the platform in the New York City subway system for the annual No Pants Subway Ride . Flashmob: A group of Tube passengers pretend not to know each other and keep a straight face as they take part in No Trousers on the Tube 2013 . On the train: A group of no-pants riders travel between Central Station and North Sydney station in Sydney, Australia . Revelers: A man enjoys the view aboard a train in Sydney, Australia . On the group's website, Improv . Everywhere said that the only two requirements for participating were a . willingness to ride the subway without pants and the ability 'to keep a . straight face about it.' Despite the threat of snow and bleak . midwinter temperatures in London, many thrill seekers braved the weather . and took to the London Underground in the UK's own version of the . event. Participants behave as if they do not know each other and - other than the lack of trousers - dress appropriately for winter donning hats, scarfs and a warm coat. The hilarious craze started back in 2002 when a handful of New York pranksters decided to cause a stir on the subway. Getting comfortable: A pantsless female rider in Sydney, Australia, takes her seat on the train . Barefaced cheek: Two female participants brave the cold weather and take to the London Underground in just their underwear . Mind the gap: A gang of pranksters taking part in the London event make sure they stand behind the yellow line while waiting for their train . Disapproval: A man watches as participants in the No Pants Subway Ride take the 6 train uptown in New York . Baring all: The event was orchestrated by Improv Everywhere, a New York City-based prank collective that causes scenes of chaos and joy in public places . Just hanging around: Some riders in the New York City subway ham it up for the camera as they participate in the event . Acting normally: Those who take part are told to go about their everyday business and pretend not to know each other . Say cheese: Other fully-clothed commuters take pictures of fellow passengers who are just in their pants on a packed Picadilly Line train . Untrussed Down Under: Commuters in Sydney, Australia, also took to the train minus their trousers . Confused: Passengers were bemused by less than fully-dressed commuters at a rail station in Berlin . Colourful: Some dressed in garish underwear as they removed their trousers to take part in the No pants Subway Ride in Berlin today . Pantsless: Several riders in the New York City subway stand on the platform in their underwear . Spectacle: Bemused riders watch as participants in the No Pants Subway Ride take the 6 train downtown . Surprise: Passengers on a Shanghai train look startled as one passenger, complete with warm jumper and wooly hat takes off his shoes and trousers . Untrussed: Passengers on a Shanghai subway train might have their umbrellas to protect them from the rain, but they are likely to get wet legs without their trousers . Suiting up: Participants shed their clothes to take part in the annual No Pants Subway Ride in Stockholm, Sweden . Pants off: Participants of the No Pants Subway Ride stand in a subway train in Mexico City . One participant entered the train in . just his underwear for seven consecutive stops and, if asked, were . instructed to tell people that they 'just forgot' their trousers. On the 8th stop, a final participant would enter the carriage selling trousers out of a duffel bag - much to the bemusement of other passengers. The annual event steadily grew each year with more and more people choosing to take part. But it nearly hit the buffers in 2006 when the stunt was halted by a New York policeman. Eight passengers were handcuffed in their underwear and taken into police custody. A judge later threw out the case because it is not illegal to wear just your underwear on the Subway. Spectacle: Passengers look at a man not wearing pants, while riding in the subway during the annual No Pants Subway Ride in Shanghai, China . Sprechen sie pants? Passengers look at a man without his pants on the subway during the No Pants Subway Ride in Berlin, Germany . Bottoms up: Participants in the No Pants Subway Ride wait to board an uptown 6 train in New York . Confusing sight: A subway rider glances at a No Pants participant aboard a train in Mexico City . Acting natural: Riders resumed their usual subway activities, like reading - only without their trousers . Startling: Onlookers watch as two girls chat nonchalantly on a Shanghai train earlier today . The No Pants event went global in 2008 with Adelaide in Australia joining eight American cities in taking part in the stunt. Last year's event saw tens of thousands of people daring to bare their underwear in 59 cities in 27 countries around the world. In London alone more than 150 took part. This year Londoners startled fellow passengers on the Picadilly Line. Unlike freezing London participants, those who took part in New York enjoyed a mild winter day, while those who took off their trousers in Sydney basked in balmy summer weather. Events also took place in cities such as Sofia, Stockholm, Berlin and Beijing. Strange: Passengers react to seeing a man without his pants on the subway during the annual No Pants Subway Ride in Shanghai, China . Hilarious: A group of men share a laugh as they take part in No Pants Day in Sofia, Bulgaria . Under-dressed on the underground: Fellow passengers smile as two commuters board the train holding their trousers in the Bulgarian capital . Sofia so good: Passengers without pants queue to board a train and provide amusement to fellow travellers on the train in Sofia . Undressed to impress: One commuter with a particularly loud pair of pants stands on the platform of a station in Stockholm .
Commuters in cities around the globe took part in the annual No Pants Subway Ride .
Passengers were undressed to impress in New York, London, Madrid, Mexico, Berlin, and Stockholm .
By . Steve Nolan and Thomas Durante . PUBLISHED: . 21:22 EST, 13 January 2013 . | . UPDATED: . 23:18 EST, 13 January 2013 . Bare-legged riders around the globe braved the winter weather and some stares from fellow commuters on Sunday for the No Pants Subway Ride - an annual celebration of freedom, subways - and skivvies. After events in cities like London and Madrid, North America followed suit, donning just their briefs and boxers in cities like New York, Boston, Philadelphia and Mexico City. It started off as a prank by comedy group Improv Everywhere that bemused a few embarrassed commuters but has since grown into a global phenomenon. Scroll down for video . Naked ambition: Some New York City riders ditched their shirts as well as pants during the annual event . Conspirators: A group of pants-less tube riders go about their business on the London Underground in celebration of the city's No Trousers Tube Ride 2013 . Forgetting something? Commuters line up on the platform in the New York City subway system for the annual No Pants Subway Ride . Flashmob: A group of Tube passengers pretend not to know each other and keep a straight face as they take part in No Trousers on the Tube 2013 . On the train: A group of no-pants riders travel between Central Station and North Sydney station in Sydney, Australia . Revelers: A man enjoys the view aboard a train in Sydney, Australia . On the group's website, Improv . Everywhere said that the only two requirements for participating were a . willingness to ride the subway without pants and the ability 'to keep a . straight face about it.' Despite the threat of snow and bleak . midwinter temperatures in London, many thrill seekers braved the weather . and took to the London Underground in the UK's own version of the . event. Participants behave as if they do not know each other and - other than the lack of trousers - dress appropriately for winter donning hats, scarfs and a warm coat. The hilarious craze started back in 2002 when a handful of New York pranksters decided to cause a stir on the subway. Getting comfortable: A pantsless female rider in Sydney, Australia, takes her seat on the train . Barefaced cheek: Two female participants brave the cold weather and take to the London Underground in just their underwear . Mind the gap: A gang of pranksters taking part in the London event make sure they stand behind the yellow line while waiting for their train . Disapproval: A man watches as participants in the No Pants Subway Ride take the 6 train uptown in New York . Baring all: The event was orchestrated by Improv Everywhere, a New York City-based prank collective that causes scenes of chaos and joy in public places . Just hanging around: Some riders in the New York City subway ham it up for the camera as they participate in the event . Acting normally: Those who take part are told to go about their everyday business and pretend not to know each other . Say cheese: Other fully-clothed commuters take pictures of fellow passengers who are just in their pants on a packed Picadilly Line train . Untrussed Down Under: Commuters in Sydney, Australia, also took to the train minus their trousers . Confused: Passengers were bemused by less than fully-dressed commuters at a rail station in Berlin . Colourful: Some dressed in garish underwear as they removed their trousers to take part in the No pants Subway Ride in Berlin today . Pantsless: Several riders in the New York City subway stand on the platform in their underwear . Spectacle: Bemused riders watch as participants in the No Pants Subway Ride take the 6 train downtown . Surprise: Passengers on a Shanghai train look startled as one passenger, complete with warm jumper and wooly hat takes off his shoes and trousers . Untrussed: Passengers on a Shanghai subway train might have their umbrellas to protect them from the rain, but they are likely to get wet legs without their trousers . Suiting up: Participants shed their clothes to take part in the annual No Pants Subway Ride in Stockholm, Sweden . Pants off: Participants of the No Pants Subway Ride stand in a subway train in Mexico City . One participant entered the train in . just his underwear for seven consecutive stops and, if asked, were . instructed to tell people that they 'just forgot' their trousers. On the 8th stop, a final participant would enter the carriage selling trousers out of a duffel bag - much to the bemusement of other passengers. The annual event steadily grew each year with more and more people choosing to take part. But it nearly hit the buffers in 2006 when the stunt was halted by a New York policeman. Eight passengers were handcuffed in their underwear and taken into police custody. A judge later threw out the case because it is not illegal to wear just your underwear on the Subway. Spectacle: Passengers look at a man not wearing pants, while riding in the subway during the annual No Pants Subway Ride in Shanghai, China . Sprechen sie pants? Passengers look at a man without his pants on the subway during the No Pants Subway Ride in Berlin, Germany . Bottoms up: Participants in the No Pants Subway Ride wait to board an uptown 6 train in New York . Confusing sight: A subway rider glances at a No Pants participant aboard a train in Mexico City . Acting natural: Riders resumed their usual subway activities, like reading - only without their trousers . Startling: Onlookers watch as two girls chat nonchalantly on a Shanghai train earlier today . The No Pants event went global in 2008 with Adelaide in Australia joining eight American cities in taking part in the stunt. Last year's event saw tens of thousands of people daring to bare their underwear in 59 cities in 27 countries around the world. In London alone more than 150 took part. This year Londoners startled fellow passengers on the Picadilly Line. Unlike freezing London participants, those who took part in New York enjoyed a mild winter day, while those who took off their trousers in Sydney basked in balmy summer weather. Events also took place in cities such as Sofia, Stockholm, Berlin and Beijing. Strange: Passengers react to seeing a man without his pants on the subway during the annual No Pants Subway Ride in Shanghai, China . Hilarious: A group of men share a laugh as they take part in No Pants Day in Sofia, Bulgaria . Under-dressed on the underground: Fellow passengers smile as two commuters board the train holding their trousers in the Bulgarian capital . Sofia so good: Passengers without pants queue to board a train and provide amusement to fellow travellers on the train in Sofia . Undressed to impress: One commuter with a particularly loud pair of pants stands on the platform of a station in Stockholm .
cities like London and Madrid, North America their trousers . Confused: Passengers were take part in the annual No Pants Subway Ride in participants, those who took part in New York