The stalking unit was set up in direct response to the murder in 1989 of Rebecca Shaeffer, a television actress. The OJ Simpson trial, which began as a stalking case, and the prosecution of a man making threats against Steven Spielberg and his family gave the unit greater prominence and clout. Paradoxically, celebrity stalking accounts for a tiny percentage of the team's overall caseload - 90 per cent is caused by domestic friction between present or former partners. Mr Gordon and his team are reluctant to discuss the means stalkers and other criminals use to conceal their identities over the internet, but it seems many people are remarkably naive about how anonymous they can be. Special FBI computer forensics teams can locate the origin of just about anything, but most of the time such fancy technology is not even needed.
People assume computers have some kind of veil of mystery, but they are wrong.