What is going on in Britain right now is ridiculous. If rioters were raping or murdering in the open, they would be warned and then shot at. To me, there is no difference when it comes to vandalizing and looting a business.
Warn and shoot. It might take a couple of dead youths, but the riots would stop very quickly.
I'm a major proponent of deterrents. I especially believe they work well on the "devil made me do it crowd," but I'm also sure that it keeps the odd atheist from doing stupid things too.