I agree it's probably not terribly productive to just open fire on people with no regard.
My policy, in so much as I actually have one, is three tiered:
1. Ignore the total assholes, who exist in this forum to be little more than mere assholes. You'll figure out who they are pretty quick. I don't even read their posts. If you have to use ignore, use it. I would recommend doing that for most people. It really will improve your DC experience tenfold.
2. Take it easy on folks you're not too familiar with. Give them the benefit of the doubt, trust me if they don't deserve it, they'll squander it almost immediately and you can discard them to my previous point. For me personally, unless someone tries to take a rhetorical potshot at me first, I'm not interested in engaging in anything too nasty or mean spirited.
3. Know that it will be a lot different with some of the folks around here who have argued with each other for years, now. Baby Lee made this point earlier. We're more comfortable with each other, we like each other more and "get" each other's styles more than folks who have just started interacting. So we'll get a little rougher with each other but that's because, I assume, we know each other pretty well and feel more comfortable exchanging barbs.