The way you can tell if someone is a movie snob is by asking them what they like to do in their spare time. If they say "movies" they are normal people. If they say "film" they are movie snobs. Movie snobs are the kind of people who go see a movie like Spiderman and then whine that it's unrealistic because there's no way a real person could get bit by a spider and be able to fly from building to building.
You can usually find movie snobs posting 1000 messages a minute on imdb.com trying to make themselves look smarter than other people and telling everyone else they are using bad grammar. Chances are they are in their mid-20s, don't have jobs, and live in their mom's basement. They might try to make independent movies but don't realize that everyone else thinks their movies are terrible.