Who owns street art?

A man walks past street art in east London, Thursday, Dec. 20, 2012. The clock is ticking down to Dec. 21, the supposed end of the Mayan calendar, and from China to California to Mexico, thousands are getting ready for what they think is going to be a fateful day. The Maya didn't say much about what would happen next, after a 5,125-year cycle known as the Long Count comes to an end. So into that void have rushed occult writers, bloggers and New Age visionaries foreseeing all manner of monumental change, from doomsday to a new age of enlightenment. (AP Photo/Matt Dunham)
A man walks past street art in east London, Thursday, Dec. 20, 2012. The clock is ticking down to Dec. 21, the supposed end of the Mayan calendar, and from China to California to Mexico, thousands are getting ready for what they think is going to be a fateful day. The Maya didn't say much about what would happen next, after a 5,125-year cycle known as the Long Count comes to an end. So into that void have rushed occult writers, bloggers and New Age visionaries foreseeing all manner of monumental change, from doomsday to a new age of enlightenment. (AP Photo/Matt Dunham)

Who owns public art illegally placed onto private buildings? A recent debate arose when famous Banksy work in London entitled "Slave Labour" was ripped out of the side of a building, shipped across the Atlantic, and put up for auction with an estimated final price of over half a million dollars.