You know it is depended on viewers. If one is enough aware about watching movies then I don't think there will be negative effect of movies. Even one can take porn movie positively. Let me give you an example- By watching movie named 'Ramayana ' one can't argue that one is becoming like 'Ravan' by inspiring from the movie.
One can also be 'ram' if one wants to be. My point is it is depended on viewers. And besides;One can't take movie as a medium disappear in virtual world. Because this virtual world is going to end soon. You have to face reality. You can't conclude your situation good or bad based on movie. Cos Conditions in the movie is totally different than your reality. So watch movie with your full awareness. And enjoy virtual reality!