The media have been talking about how some rioters in London have been using smartphones and social media sites to coordinate their movements to avoid being caught by the authorities. Zack Whittaker at ZDNet wrote that while some people are using Facebook and Twitter, one of the tools of choice is the BlackBerry Messenger, which encrypts messages so they can’t be read by third parties.

For its part, Research in Motion (RIM), BlackBerry’s parent company, said it would cooperate with the authorities to identify people alleged to have participated in the riots, though according to the BBC the police have to prove they know the identities of the phones’ owners under the Regulation of Investigatory Powers Act before they can acquire the records, rather than searching messages for people using riot-related keywords in text messages, e-mail and social media posts.