First off, the node you mentioned was posted anonymously, so there's little we can do to "control" the person in question, unless someone happens to discover who posted it.
In my experience, trolling is an episodic and periodic behavior. There have been a few determined, um, er, activists, but it seems they've mostly wandered off or taken friendly advice to heart. (And, just about everyone has had a bad day once or twice.)
In the most extreme cases, we need to trust the existing infrastructure.
The most offensive or off-topic messages can be, um, archived. And, if we (as members) find something particularly offensive, we can ask that it be reviewed for further action.
Also, the Reputation system is a powerful motivator for most folks.
In my experience, the Monestary benefits from a little agitation. When that gets out of hand, it gets responded to quickly and appropriately.
P.S. I like little's idea. fwiw.