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.”