Why are famous killers famous for killing?

Like it or not, human nature is facinated by horror and the macabe. It's comparable to people in passing cars that can't take their eyes off an automobile accident. Killers get far more attention than they should but as long as people are horrified by their crimes they will get noticed.

There are now laws that prohibit killers from benefitting financially for their misdeeds. This includes book deals, movies (TV or theater), interviews, artwork or handmade crafts. I also find it hard to believe that some serial killers actually have fan clubs. Scott Peterson sits on California's death row at San Quenten but gets fan mail by the bagsfull. He is refered to by his many female fans as Hottie Scottie and he never has a shortage of marriage proposals.