Techniques for Scary Stories. What makes them scary?

Most scary movies and stories that I have seen or heard involve death. The public finds death and murder a scary situation so it makes sense to incorporate the feelings and fears of the public into the scary production. Why is everyone afraid of Freddy Krueger? Mainly because he kills people in their sleep. No one wants to be murdered and this is a sense played to the storytellers benefit. Stories are also scary because of the thrill and when they make you "hang on by the edge of your seat". When the protagonist or side character is hiding from the "boogie man" in the closet and the door just rips open is when everyone in the theatre screams. This is the thrill portion of a scary movie. The story line of these movies and stories are awful. I think this happens because the writers try too hard to scare people than writing a decent plot. There are many things that make a movie scary. Why is Jason scary? Jason wears a hockey mask and walks around with a machete. The mysteriousness of him is what scares people along with the fear of being hacked up by a six foot five man who cannot be harmed. That is part of the poor plot aspect. You know when Jason is in the same room as a person that they are going to be killed off because you cannot harm Jason. You know what is coming. I am a fan of scary movies though. I know a lot of kids do not like almost peeing their pants every five minutes but I think it is the adrenaline of the situation the characters are put into that draws me in. I like the rush of the people trying to solve the mystery or stop the killer and how they do it. Its like a giant puzzle and I like to learn how they put the pieces together to stop him. Identity also seems to be a huge part of the fear factor. Freddy's face is all cut up and he has knives for fingers, Jason wears a hockey mask and carries a machete, Michael Myers wears a mask, It is a scary clown.