By far, the most terrifying film you'll ever see. It will shake you to your core. A film that has shocked audiences everywhere they've seen it. There's nothing scarier. … If these lines from a movie trailer make you think you're about to see the next big summer horror blockbuster, then you're in for a surprise. For it turns out that the most terrifying movie of the summer -- the film that has audiences on the edge of their seats, gripping their popcorn tubs in panic and grabbing on to their dates -- is a documentary on the perils of...