Riots spread through UK cities

Looters are apparently now going into people's home to loot, according to a friend of mine over there.  More from NPR:

A wave of violence and looting raged across London and spread to three other major British cities Tuesday, as authorities struggled to contain the country's worst unrest since race riots set the capital ablaze in the 1980s.

In London, groups of young people rampaged for a third straight night, setting buildings, vehicles and garbage dumps alight, looting stores and pelting police officers with bottles and fireworks. The spreading disorder was an unwelcome warning of the possibility of violence during London's 2012 Summer Olympics, less than a year away.

Police called in hundreds of reinforcements and volunteer police officers— and made a rare decision to deploy armored vehicles in some of the worst-hit districts — but still struggled to keep pace with the chaos unfolding at flashpoints across London, in the central city of Birmingham, the western city of Bristol and the northwestern city of Liverpool.

I've never understood the public's reticence about taking on looters/rioters with force. Especially once they start breaking into private homes, with people living there, all bets are off in my book. You no longer have a social justice gripe when you're breaking into private homes, and smashing the window on the local Foot Locker because you want to grab ten pairs of sneakers.  And yes, there's the concern of "police violence creating even more rioters", but that's not what I'm talking about. I've been surprised in the past, when these situations arise, when I ask friends, why don't the police tell the looters to stop or they'll shoot?  And friends say that shooting them wouldn't be right.  Why?  And again, we're not talking about peaceful protesters here, or some folks holding a sit in.  We're talking setting things on fire, looting and burning down someone's livelihood, and breaking into your home in the middle of the night.  Is it acceptable, morally, to use violence to stop that (regardless of whether it's wise, in terms of fomenting more violence)? What do you think?

Here's at least one photostream I found on flickr of some amateur shots. More here. And another.