Droz and his faulty reasoing...

In the movie, PCU, an "appeal to ridicule" logical fallacy that can be found in the quote from Droz, "What's this? You're wearing the shirt of the band you're going to see? Don't be that guy." By mocking someone who wears any attire of the a group whose concert they are going to, he is saying that it is stupid and wrong to do that. This sort of reasoning is not valid because mocking a claim does not show that it is false.