Facing a public backlash against police restraint during four nights of rioting, Prime Minister David Cameron offered his toughest line yet on the violence, saying Wednesday that officers were authorized to use rubber bullets and water cannons in what he described as a “fight back” to retake English streets. As Anthony Faiola reports:

Cameron’s comments came as Britain, a nation of laws and a leading critic of crackdowns by totalitarian governments overseas, engaged in a heated debate over the methods it should use to combat lawlessness at home. As reinforcements rushed to bolster police forces overwhelmed on Tuesday in Manchester and Birmingham, officials also warned that frustrated citizens were grouping together and sliding into vigilantism.

As of late Wednesday, however, much of the country appeared calm, with stores reopening in some hard-hit neighborhoods, albeit with a large police presence on the street. But many people still spoke of a sense of fear after the most deadly night of the riots yet, with authorities in Birmingham calling for calm amid fears of rising racial tensions after a fatal incident.

Late Tuesday, a car with alleged looters ran over and killed three South Asian men who were out protecting their neighborhood. Birmingham police arrested a suspect; though they did not disclose his race, missives circulating on Twitter said the driver was black, ratcheting up local tensions.

Among the dead was a 21-year-old whose father, Tariq Jahan, gave him CPR on the scene only to watch him die. In an emotional appeal, Jahan begged for an end to the violence, saying the tragedy should become a turning point for peace and not a rallying cry for “revenge.” “I can’t describe what it is like to lose your son,” he said. “I don’t know what is happening to England and why innocent people have to die.” He later added, “Blacks, Asian, whites, we all live in the same community, why do we have to kill one another?” He asked that all honor his son by “not going out tonight.”

The use of social networking and mobile phone messaging in organizing rioters has led some to call for the suspension of some services while law enforcement restores order. As the Post’s Melissa Bell explained:

The quick spread of the riots and violence in London over the last few days seem to have taken Britain by surprise. Not enough police were on the streets; the prime minister did not come back into town until two days of violence rocked the city; and, Monday night, the violence spread to cities beyond London.

It seems the rioters had a key assist from a technology not often making headlines: BlackBerry Messenger (or BBM for short). It’s put Blackberry at the center of the riots, with a London MP asking the company to turn off the technology to calm the chaos and a hacking group infiltrating the Blackberry site threatening riots at the Blackberry headquarters if the company releases any BBMs to the police.

While Twitter and Facebook have gotten the lion’s share of attention in helping to fuel protests in the Middle East, the public nature of those sites has kept most Londoners away from the open networks. The Guardian reports that many of the rioters organized on the private messaging system BBM, which allows for a group text messaging to be sent to people within a chosen network.

A recent study showed that more young adults between 16-24 prefer the less expensive BlackBerry phones than other smartphones.

Now, David Lammy, member of Parliament for the restive Tottenham neighborhood, has called for BlackBerry to suspend its service to quell the riots. BlackBerry had previously released a statement that it is willing to work with the police to assist with any riot investigation.

Rioters and eyewitnesses are posting images of the events unfolding across Britain online in large numbers, but some images that were spread through social networks were later revealed to be misinformation. As Katie Rogers reported:

As images published by eyewitnesses to the London riots over the past three days continue to reach the Internet in real time, impostors are making their way into the mix.

The latest images aren’t even doctored, just photos submitted from other events. They’re easy enough to vet, but because of the breakneck speed at which social media can give context through imagery — and the speed at which “mainstream” media works to catch the flow — the photos have become representative of the London riots in their own right.

Monday evening, New York Times reporter Brian Stelter tweeted two images of a tiger that rumors said had escaped from the London Zoo. Stetler tagged the photos as unconfirmed, but Guardian reporter Richard Adams called him on it anyway, pointing out that no animals had escaped from the zoo.

In an effort to bring clarity to the calamity of breaking news, the Guardian’s data blog is tracking each outbreak of rioting across the U.K. after each event is verified. However, the blog is still allowing eyewitnesses to submit and geotag riot photos to its Flickr pool without similar vetting filters.

More from The Washington Post

Cameron pledges more arrests

Looting, arson spread widely in London as civil unrest escalates

Tottenham stadium ticket offices damaged