I must not be a member of the communities where these discussions occur, because I never see any of this for myself. Sometimes I hear secondhand from someone in my flist about a feud between fanfic writers or some SPN wife-bashing or some kerfuffle about the show, but I've never witnessed it. The behavior I have heard about though certainly does make me think we could all be more civil.

(Does my own Sera-bashing and rants about some really terrible writing during seasons 6 & 7 count?)

I have been horrified at some fan behavior at Cons, but don't think any guidance from me would be welcome. I get enough crap for telling the people sitting behind me to stop talking during the panels.