As the riots in London look set to continue for a third night — and to spread to other parts of the UK — details are starting to emerge on how the rioters have been organizing themselves. The medium of choice? BlackBerry Messenger.

The riots began as a protest at the police shooting of Mark Duggan, a resident of the Tottenham area of north London, last Thursday. A Facebook group quickly sprung up to commemorate Duggan; police and media attention was drawn to a particular post on the Facebook page which appeared to fan the flames, as well as the occasional tweet from rioters describing their deeds and where they were headed next. Some posted pictures of looting and burning police cars.

But it soon became clear that BBM was by far the most popular means for rioters to communicate. BlackBerry devices, cheaper and more widespread than iOS or Android smartphones, are owned by more than a third of British teens, according to a recent study. BBM — an instant message service for BlackBerry owners — is free, instantly available, one-to-many, and the authorities can’t immediately trace it. BBM users must exchange PIN numbers, which keeps their conversations private.

The Guardian got its hands on BBM messages directing rioters — blasts that are shocking in their specificity. “Everyone in edmonton enfield wood green everywhere in north link up at enfield town station at 4 o clock sharp!” reads one. Another directs looters to Oxford Circus in the heart of London: “SHOPS are gonna get smashed up so come get some (free stuff!!!)”

Research in Motion, makers of BlackBerry, responded with this tweet: “We feel for those impacted by the riots in London. We have engaged with the authorities to assist in any way we can.” That seemed to suggest that BBM would not be as private as some of the rioters might have hoped, but RIM refused to say exactly how much information it would be sharing with police.

The BBM connection didn’t stop one of London’s chief law enforcement officials from tarring all of social media with the same brush. “Really inflamatory” messages on Twitter were mainly to blame for the disorder, said Steve Kavanagh, the deputy assistant commissioner of the Metropolitan police at a press conference Monday. “Social media and other methods have been used to organise these levels of greed and criminality,”