Since movies are the subject I can't help but think of Cabin in the Woods (which also had some very creepy undertones that reach farther than just a mere movie) and something that was said about them putting all sorts of red flags and clues about but the sacrifices had to make the choice to ignore them. They had to choose to ignore the Harbinger and proceed down the road anyway it was through that choice to ignore that they basically gave their consent for what was to follow. Maybe clues get dropped in movies because thats the thing that people pay the most attention to. Thats why things like product placement within film matter so much. Sad thing is, even if you put warnings on billboards....place harbingers of doom at every intersection....people will still proceed further, ignoring them. Too many have to learn the hard way.