Why the Riots in London?

I've been following the riots in London with great interest.  Partly that's because I hope to travel to Great Britain in the coming years, and partly because what takes place in Great Britain eventually takes place in the United States.  A couple of articles especially were helpful to me.  Here's the first one and here's the second one.  I'm sure they'll be helpful to you as well if you have time to read them.