When a Stranger Calls

Has anyone seen the previews for this movie?
The plot summary is as follows: A young high school student babysits for a very rich family. She begins to receive strange phone calls threatening the children. When she finally realizes that it's not a joke, she calls the police, only to find out that the call is coming from inside the house.
I have done a LOT of babysitting and this movie is basically my worst nightmare of what could happen when you're babysitting. A weird phone call...the creaks and sounds of a house you're not familiar with. The scary feeling that someone is watching you. This movie would be such a nightmare to watch. I mean...really? Who wants to watch a movie about a poor teenage girl being harrassed while babysitting? Clearly you don't want to watch it if you're a babysitter. You also don't want to watch it if you're a parent. Kids certainly can't see it. So I've concluded that they only people that want to see a movie like this are crazy psychos that would actually threaten a girl babysitting.
Anyway, those are my thoughts on this crazy movie. If you see it, let me know what you think.