The investigation into the shocking murder of English student Meredith Kercher has uncovered a wealth of mobile and Internet-related evidence.
The main suspect, Raffaele Sollecito, blogged on 13 October 2007 that he wanted to try "extreme experiences". With his girlfriend Amanda Knox he was tracked on the evening of the murder to a meeting with the third suspect Diya Lumumba; they returned to Kercher and Knox's flat, where they switched off their mobile phones. Lumumba's later claim that he was running his bar at the time was shown to be highly unlikely, based on the timestamped receipts in the bar till.
The following lunchtime the Postal Police of Perugia visited Knox's flat because another flatmate's mobile phone (in recent use by Kercher) had been found in a neighbour's garden. They disturbed Sollecito and Knox, whose claim they were waiting for the Caribinieri was later shown to be false based on the timing of their call to the police.
Police searched Facebook for information related to Kercher, in particular to identify friends they could interview. Sollecito and Knox also had a wealth of personal information on MySpace, Facebook and YouTube.
Of course, as Cardinal Richelieu observed: "If you give me six lines written by the most honest man, I will find something in them to hang him." It will be interesting to see if all of the publicity around this case causes any shift away from the self-publicising culture of social networking sites.
If you are interested in finding out more, last year I wrote a research note on the powers that the UK police and other government agencies have to access such personal information. In September I gave a joint conference presentation on Facebook's privacy controls. I also just did an interview for Sky News.