Must applaud the director for his bold choice (SPOILERS)...
I thought it was genius to film almost the entire movie through the supposed lens of hidden cameras. There may have been a couple of times where the director cheated, but almost every shot is seen through a hidden camera placed by or carried by the Hanks character.
When Hanks' character is spying on Amy, we see her outside the house but we aren't allowed to see inside the house until he sets up the cameras. This really enhanced the voyeuristic tones of the film and really made you feel like this was a violation in a way that traditional third person POV filmmaking would not have been able to do.
I'm surprised more people aren't praising this very creative and creepy little film. I expect it's because not many people have seen it. But it's definitely a hidden gem (though I didn't like the ending and the lack of accountability for the crimes).
But then again, I would have expected nothing less than a non-traditional ending in a non-traditional movie.