Above is a video by a graffiti artist named Momo about writing a tag the width of Manhattan by dripping paint from a can attached to the back of his bike. The tag was done in2006 but went unnoticed for several years and has recently been featured in this piece in the NY Times.
The video below is called The Leak and was made by Francis Alys in Paris in 2006. This video and others by Francis Alys are available to view or download and share under a creative commons license from his website http://francisalys.com/public.html
"These videos can be downloaded and shared with others as long as the authorship is credited and there is a link back to the website of the author. These videos cannot be altered in any way or used for commercial purpose."