Additionally, let's not discount the amount of internet Asperger's that tends to take place on message boards. Without tonal or visual/facial cues, it's tough to tell what the intention behind a lot of posts are. Sometimes what a GM means to be a joke is taken seriously and vice versa, which harbors bad feelings - especially in an environment when you're dealing with the same people over a period of several weeks. Grudges arise, subside, etc.