It pains me to do this but some people are just jerks. So here goes, a few guidelines adopted from DCist, I'm reluctant to say rules:
* Good comments can disagree with the content in the post, but they never insult other commenters.
* Good comments are usually pretty short and are open to being contradicted by other readers.
* Good comments are always on topic, and never contain spam or spam-like content.
So in sum, don't insult and curse at specific people. Don't write a thesis in the comments section, especially about something totally random. Don't steal. Honor thy mother and father etc. etc.
I will delete comments that regularly violate the guidelines. So don't get all sore if you write "Jim is an asshole" and I delete your entire comment. You can however write "muggers are assholes." We cool?