Twitter users could face arrest for inciting violence in the wake of two nights of unrest in London, a Scotland Yard chief warned today.
Deputy Assistant Commissioner Stephen Kavanagh confirmed officers were looking at the website as part of investigations into widespread looting and rioting.
Acting Commissioner Tim Godwin pledged a robust response to some of the "pure criminality" seen in recent days.
Amid speculation that police could have done more to contain the eruption of trouble, Mr Godwin said he was immensely proud to be a Scotland Yard officer.
He went on to praise the "sheer bravery" of officers who were injured during the clashes.
Police patrols will be stepped up again tonight with many officers voluntarily abandoning scheduled leave, Mr Kavanagh said.
Opportunist rioters over the past two nights are believed to be aged from their mid-teens upwards, he added.
Last night's wave of looting was "disgusting behaviour, ripping apart people's livelihoods and businesses".
He vowed to deliver "speedy justice" for Londoners in the wake of the violence.
Some messages posted on Twitter surrounding the riots had been "really inflammatory, inaccurate", Mr Kavanagh added.
When asked by reporters whether officers would consider arresting tweeters in relation to incitement to violence, Mr Kavanagh said "absolutely".
He later added: "That investigation is already under way and that is exactly the sort of thing we are looking at."
Mr Godwin said the force needed to look at events leading up the riots but said he was "immensely proud" of some of the actions of his officers on Saturday night.
"I was immensely proud, as I have always been, to be a member of the Metropolitan Police Service.
"The sheer bravery, the determination and the resilience of the men and women of the Metropolitan police could be seen from all the images that we had."
He said "I don't want to lose the good work" and progress that had been made in Tottenham in recent years.
"Will we look at what's gone on here? Of course we will.
"But at the same time we will make sure that the stuff that we have seen come off the back of this - which is pure criminality, opportunistic criminality - is dealt with firmly and robustly."
Mr Godwin said he had spoken to the Prime Minister, the Home Secretary and the London Mayor about the events over the weekend.
Mr Kavanagh, who said he had been asked whether the force was in crisis, insisted Scotland Yard was "pulling together" to deal with the disturbances.
He added: "Naturally the Met is hugely disappointed at the loss of recent senior staff but the Met bounces and it will respond to these challenges in the way that it always has been - by very effectively working with local people."