London is the home of many famous street artists like Swoon (above) and Banksy (below), but the majority of the graffiti is done by anonymous citizens with unique points of view.
This piece "Scary" (below) is a land mark on Curtain Road, famous among the locals.
The neighborhood Shoreditch (where I live and study abroad in London) is known to have the most works of street art and often hosts gallery shows of work by well-known street artists like Shepard Fairy and Banksy (below).
It is sometimes even encouraged for commercial purposes (above) and decoration (below), especially on Brick Lane.
Katie Buckleitner-- London Mojo