Only when they are dead wrong.
You know, if someone experiences a movie / game or w/e and doesn't know any better, i can live with that. You could always tell him about the source material if he wants.
Now the one time i did get quite annoyed and was dieing of laughter at the same time, was when some 16y/o boy tried to tell me that some bullshit rapper {one of those top 40chart kind) created, and was the first to use, this
Now that pissed me right off. Specially since dumb cunts (pardon my language, but you didn't meet this people, they really were) believed him.