I've never been warned, which leaves me feeling a little left out...
If you live in Canada, Western Europe or the U.S., there's an instinctive distaste for warnings about what we say, because of our tradition of wide and free-ranging speech. The warnings become somewhat more problematic if there are no guidelines as to what is permitted and what isn't.
However, as you can see by trying to make sense of a thread on DP Review, where you spend half your time opening messages that turn out of be trolls, or time-wasting assaults on somebody else, etc., and where even the simplest questions are often answered with insults, there is much to be said for civility and some kind of enforcement of it. There's a lot of good information on DP Review, but sometimes getting to it can be too much trouble. I wouldn't like to see that happen here.
So let me suggest some guidelines.
-Act like an adult. It's not that hard.
-If somebody insults you, turn the other cheek. It's the other guy who's the dimwit, or the hormone-inflicted adolescent.
-If you're writing a post and realize that you're geeking out, stop and rewrite.
-Don't embellish technical arguments or debates with invidious characterizations of your opponent's intelligence.
-Be careful with humor; what's funny to some people isn't to others. Doesn't mean you can't attempt humor, but be careful with it.
-Recognize the point when a discussion becomes a yes it is, no it isn't affair (also called a he said/she said argument.) At that point, nobody's mind's going to change, and that's where the insults often start.
At the same time, I don't think it hurts to be vigorous in your positions; extremely vigorous. But it you keep the argments on a technical level, or make clear that aesthetic arguments are personal points of view, and that contrary opinions don't necessary mean that you think those opinions are held by morons, then we should be all right.
I personally will say that I am extremely tired of Internet BS. All I want is a little interesting discussion/conversation from people who have interests that are similar to mine, without getting into the childish name-calling crap.