I think the perpetrators are psychopaths, not sociopaths. They act without any care for their victims. Little Hawk's comment was a good one. These are what I used in my teaching days to call The Unloved. Strangers to love, attention, care and affection, abused and neglected, they have no concept of others' needs or suffering. They are indeed angry and extremely dangerous. I am not favouring any particular form of punishment or treatment (even if one could identify and catch them) But loved and cared-for humans do not do these things.