Police chief warns Twitter users they could face arrest for inciting violence

TWITTER users could face arrest for inciting violence in the wake of the rioting in London, a Scotland Yard chief has warned.

Deputy Assistant Commissioner Stephen Kavanagh confirmed that officers were looking at the website as part of investigations into widespread looting and rioting.

Some Twitter users made use of the site to publicise the riots that were taking place. For example, one picture of a police car on fire in the Tottenham area was re-tweeted more than 100 times within an hour.

The social microblogging site has also been used to plan disruption and demonstrations, with some users understood to have tried to rally protests around Hackney Carnival on Sunday, before they were thwarted by police. Mr Kavanagh made clear yesterday that police were investigating the use of Twitter in the outbreaks of civil disobedience across the city.

He said: "Social media and other methods have been used to organise these levels of greed and criminality."

Along with the social microblogging site, it is understood many of those who took part in the demonstrations used a private messaging service exclusive to BlackBerry mobile phone handsets.

The comparatively covert messaging service, known as BlackBerry Messenger (BBM), is popular among young people as it allows them to communicate with other BlackBerry users for free. The one-to-one messages are largely untraceable - they are strongly encrypted using an algorithm called Triple-DES, which makes them unintelligible to observers.

One influential blog, Urban Mashup, revealed yesterday that word of a revolt on the streets of Tottenham started spreading among users of the smartphones as early as Thursday, hours after Mark Duggan was shot by police officers.

Jenny Jones, former deputy mayor of London, blamed an under-resourced Metropolitan Police force for missing the tweets and the status updates.

She said: "It's quite possible if they had more resources they could have picked up on this."

To a lesser extent, Facebook was used by those involved in the looting, with one youth attracting widespread attention yesterday after posting a photograph of himself alongside his haul from a series of high street shops.