My opinion of this movie increased after reading some comments here

I didn't like this movie very much while I wacthed it. It was good enough to get some thrills. But it was nothing very outstanding.

But as I came here, I was really shocked by some of the comments. I learned that a few viewers had actually thought that the "real footage" in this movie was a real footage obtained from police or medical archives. Most people did not fall for that, of course, but there were some. And that is enough.

Having learned that, I must say that this movie was actually quite successful. It managed to trick some viewers. Today, everybody is used to the "found footage" style movies. But this movie invented a different trick - Milla Jovovic appearing at the start, saying that part of the movie is dramatization, created an illusion that the rest, the non-dramatized part, might actually be a real thing. That trick was much smarter than I initially thought.