Why are you assuming that the movie watchers are watching filthy movies? In that case should they assume that you are going into filthy areas on the internet? Assumptions can be made both ways.
Therefore it is better to be dan l’kaf zchus and NOT make assumptions and to be careful what you think and what you say to other people. You are walking on very judgmental ground. You have your reasons to be on the internet and other people have their reasons to watch movies. Enough said.