Artist: JR

Do a google image search on JR and you'll come up with some interesting results. JR is the winner of the 2011 TED Talks conference money and his actual identity is still supposedly unconfirmed. 

"He has described himself as a "photograffeur", he flyposts large black-and-white photographic images in public locations in a manner which is similar to the appropriation of the built environment by the graffiti artist. He states that the street is "the largest art gallery in the world." He started out on the streets of Paris. JR's work "often challenges widely held preconceptions and the reductive images propagated by advertising and the media (Wikipedia) "