This happended in NY last month. There is a store front window near to a hotel at Lexington Avenue that hosts art shows of any kind. In June they had a show called "uncovering" - and that is what the artists did. They undressed right in front of all the bystanders outside the window. Lots of cell phone recordings there. Here is mine, there must be plenty of them out there.
There is also a pro-film of the event:
http://www.vimeo.com/25830132