To be honest, after watching the trailer, it scared the shit out of me. I'm a HUGE fan of these kind of movies, always loved the paranormal.
After getting into the movie, i started to kinda slowly freak out, because everything was so god damn creepy, no music when things was about to happen, only this loud humming sound, and that scared the shit out of me, i bet there where a lot of people that wish they had a blanket they could pull over they're head when that humming sound came. I did.
The movie is about a couple that has recently moved into a new house, when suddenly bizarre things are about to happen, so they start to film everything to see if they could catch something on tape, and they do, more and more and more for each night.
I haven't been this scared since "The Exorcist", and that movie still creeps me out. Paranormal Activity is a movie based on a true story, or they want people to think it is. To be honest, they had me there, so i checked it out to see if it was true, and it wasn't, but anyway a great concept. For you who didn't know, this movie is actually from 2006, and was released by Paramount in 2009 after Steven spielberg actually saw it (i think i read that somewhere).
The movie is shocking and scary, and if you haven't seen it, you really should do that, because this movie will give you nightmares for a long time.