Warning: Images below are NSFW.
So many butts.
Cyclists bared it all Saturday in honor of World Naked Bike Ride Day, an annual event dating back to 2004, which asks commuters to, well, do exactly what you'd expect. The event, held in more than 20 countries worldwide, has the dual purpose of "protesting against oil dependency" and "celebrating the power and individuality of our bodies."
While Saturday is the official day to go au naturale, various cities hold their bike rides on different days throughout June. Check out pictures from London, Chicago and Toronto, who held their no-clothes spin this weekend.