Commentary: attacks on Royalty--the more we know, the more we can classify.

Over the past 20 years stalking has increasingly been construed as a social, legal, and psychiatric problem that is distressingly common, causing significant harm to victims. Research in this area has demonstrated that there are recognizable features that groups of stalkers share and, by increasingly sophisticated classification, it is possible to make predictions about this phenomenon. It is anticipated that a new proposed classification can increase our ability to manage risk.