I remember the part in 'Something About Mary' when Ben Stiller explains to Matt Dillon that he only wants to get in touch with Cameron Diaz 'to see if he can help her' and the Dillon character says 'uh huh...stalker job'. There are all sorts of stalkers, which this book details effectively, from the out and out violent psycho to the dribbling, sad, undoubtedly friendless, internet stalker. Leaving aside the more extreme, the others are fundamentally not very successful people who gravitate towards other people's lives, having not much of one themselves. They are drawn, like moths to a candle, to people with more talent, beauty, charisma, whatever. Should one feel sorry for the sad little men who stalk? Nah!