Demonic or just ass-hole ghost?

I understand that our spiritual or religious beliefs tend to play a big part in our everyday lives, but why are growls, scratches or other physical paranormal attacks always classified as "demonic"? If a person was a total ass-hole or worse and did very bad things (i.e. murder, rape, sadistic medical treatments, listening to the Backstreet Boys j/k) while they were alive, than wouldn't it stand to reason that they would be the same, if not worse, in death? And what is really left to stop them from trying to continue to harm people now that they are dead and trapped in this "limbo" of sorts? Maybe that's pissed them off even more. Or perhaps they weren't really all that bad in life but are just really pissed off at how they died or when they died. Maybe they just were not ready to go yet and when the living come into their space they get even angrier and try to harm them. I know there is the whole three scratch "marking" thing, but how much strength is there in the pinky really? Plus your talking about a spirit that has to gather up as much strength as possible, including draining batteries or using your energy to even make a slight noise. Maybe that's all they could mange to use. They are the stronger fingers of the four.


That's just my personal thought on it.