I'm a Londoner near some of the affected areas. The sky is not falling, London is not degenerating into lawlessness, and from what I can see from my flat window, police are responding quickly.
Other areas may be different, but London is a very large city - commenters should remember that in discussions.
That's even scarier. When we had our (ridiculous) riots here in Vancouver a couple months back, it was all in one area. Many will argue that the cops didn't do a great job keeping it under control, but at least they kept everything in a relatively small zone away from residential areas, and it petered out over the night. Doesn't the fact that they're springing up all over London point to there being a systemic problem that is provoking people to more violence? How many days has this been going on now, three? Is there an end in sight?
London is a much larger city with what seems like a lower quality of life for many people. Basically the number of potential rioteers in London is way higher than in Vancouver, so it is logical that their riots will be stronger and longer when they do spark.
It appears a known criminal (gangs, drug-dealing) with a loaded handgun was shot by police while resisting arrest; he may or may not have shot a police officer [first] at the time of his arrest ...
So if it's not gangs trying to violent show their power then what is the motivation in your opinion? Why sudden anger towards the police _from the general populus_?
FWIW the buzz appears to be "send in the troops" rather than this being in any way justified demonstration (like maybe G8 demonstrations).
Originally there was a peaceful protest over the shooting of a young man during a police operation. that seems to have been hijacked by mobs intent purely on violence.
The initial areas are fairly poor and have a history of tension with the police, but the disturbances tonight seem simply to be youths intent on causing damage and looting.
I'm not in London, these are my impressions to give you a quick answer. They may not hold up to future scrutiny.
Other areas may be different, but London is a very large city - commenters should remember that in discussions.