Tim Stone asked: New users often are not accustomed to the Stack Exchange system, and sometimes struggle to present themselves properly, either in the way they use the site or their attitude. How willing are you to work with "problematic" users, and at what point do you decide that someone isn't worth the effort?
Matthew Read answered: I don't think it's ever appropriate for a mod to give up. There are times when you might suspend someone after egregious behavior and a failure to improve, but you still give them another shot when the suspension is over. AFAIK it's up to the team to make a permanent suspension, and not the mods, and that's probably a good thing.
Matthew Read continued: As for working with problematic users -- it's important to be up front about the site policies and what's expected, and to be polite. Telling someone they're behaving badly isn't going to work if you're behaving badly yourself. I always try to point people to the relevant FAQ, Meta post, or blog post that explains the policies and their rationale. Beyond that there's not much to do besides a suspension -- hopefully a short one gives them the jolt they need.
Al Everett answered: Very willing, and I've been. Most folks are just unaccustomed to the way Stack Overflow works and only need a little gentle prodding. If they stick around they get it. If they don't, they generally get frustrated and leave. Fortunately, my fellow mods can help with persistent troublemakers. Every situation is different, so I can't really say when it's no longer worth the effort.
eldarerathis answered: In the past I've hung around pretty poor questions on SO so that I could try to coax a real question out of someone, then tried to edit stuff an explain the site as best I can. I try to do the same here, and I'm willing to give pretty much anyone a decent shot. If a user is actively resisting any reasonable offers of help or is blatantly offensive, though, then everyone might need to walk away, cool down and try again later (including official suspension, if necessary).
eldarerathis continued: Having said that: I do think some people legitimately have bad attitudes and don't want to play nice. If it becomes clear that a user falls into that category then I'd have no qualms with suspending them, outlining very clearly why they're behaving unacceptably, and letting them try again at a later point.
Bryan Denny answered: I'm very willing to help prod new users in the right direction. But if after a few times they just don't "get it" then I'd consult the others on what to do (suspension or otherwise)
Flow answered: I think that the community is our first line of defense again “problematic” users by flagging the posts. I would point the user to our FAQ, especially the “Etiquette” section. If the user doesn’t change his behaviour after the first or second reminder, appropriate actions should be considered. It always depends on the individual case.