It's an annual event known for its cheekiness. Literally. Dozens of cyclists took part in the annual World Naked Bike Ride on Saturday to protest the world's dependence on oil and promoting human-powered vehicles.

The unusual parade through the streets of downtown Ottawa stopped pedestrians in their track. Similar reactions were expressed at 70 other cities worldwide, according to the group.

The Gulf oil spill taking place right now is one example of oil dependency gone horribly wrong, the group said, hoping it would add more attention to their efforts.

The idea was created in Vancouver in 2004 and first hit Ottawa in 2005. Riders -- who also include rollerbladers and skateboarders -- say they ride naked to symbolize our vulnerability on the road.