The government is exploring whether to turn off social networks or stop people texting during times of social unrest.
David Cameron said the intelligence services and the police were exploring whether it was "right and possible" to cut off those plotting violence.
Texting and Blackberry Messenger are said to have been used by some during this week's riots.
Rights groups said such a measure would be abused and hit the civil liberties of people who have done nothing wrong.
The prime minister told MPs the government was exploring the turn-off in a statement made to the House of Commons during an emergency recall of Parliament.
Mr Cameron said anyone watching the riots would be "struck by how they were organised via social media".
He said the government, using input from the police, intelligence services and industry, was looking at whether there should, or could, be limits on social media if it was being used to spread disorder.
Under social media, Mr Cameron includes Facebook, Twitter and specific technologies such as text messaging. The semi-private BBM messaging system on the Blackberry is said to have been widely used during the riots.
Home Secretary Theresa May is believed to be meeting representatives from Facebook, Twitter and RIM (maker of the Blackberry) to talk about their obligations during times of unrest.
http://www.bbc.co.uk/news/technology-14493497