That part doesn't bother me as much I guess. I have heard women share stalker stories that started just from classes and such. If this sort of thing is something the kid enjoys, it can be done while understanding the potential problems it can create. IMO, they should have taken this more seriously especially when they found out he was buying pictures and information from people she knew locally. They didn't recognize where it was going.
On the other side, I am glad the father was armed and was able to use it. It could have been worse.