It would be a little different here, since the police have guns, and if the London situation would have broken out here, people would have gotten shot.
I too fear the prospect of civil unrest however. Remember the OWS riots? The plan to blow up a bridge? Our government has addicted people to its handouts, and when the handouts can no longer be given, you’re going to have a lot of angry, poor youths and their parents out in force. We are raising the same feral youths as in Britain, the most recent example being the little shit who shot a baby in the face.
Just make sure you have a gun or preferably guns plural. When a mob of thirteen year old hoodlums start breaking into your house, you may just need an AR-15.
Or a KelTec PMR30 (30 rounds .22 mag rimfire): 
MSRP $415 - $700+ On GunBroker.