Partially naked demonstrators ride their bicycles at the Zocalo Square,..

Partially naked demonstrators ride their bicycles at the Zocalo Square, in Mexico City, on June 13, 2009, as part of a worldwide naked cycling protest against cars, gas emission and agressive drivers. Nude cyclists are expected to ride through the streets of cities around the world, to highlight the vulnerability of cyclists on the road and protest against oil dependency, organisers said.

Partially naked demonstrators ride their bicycles at the Zocalo Square, in Mexico City, on June 13, 2009, as part of a worldwide naked cycling protest against cars, gas emission and agressive drivers. Nude cyclists are expected to ride through the streets of cities around the world, to highlight the vulnerability of cyclists on the road and protest against oil dependency, organisers said.

Naked demonstrators ride their bicycles at the Zocalo Square, in Mexico City, on June 13, 2009, as part of a worldwide naked cycling protest against cars, gas emission and agressive drivers. Nude cyclists are expected to ride through the streets of cities around the world, to highlight the vulnerability of cyclists on the road and protest against oil dependency, organisers said