One of my favourite Banksy stencils. Really simple, but very evocative.
I get a lot of queries about use of this photo. It' a very old photo, taken with an old Canon digital point and shoot. at 2.5MP. The largest size is what's available for download from Flickr (via View All Sizes).
I'm happy for you to use this photo for your own personal and not for
profit projects under a Attribution, Share Alike license. There's a
link to the license details somewhere on this page.
If you do use it please drop me a line to say so as it's nice to know where it's ending up.