Yes. In 2008, I had a member ask a question regarding the features on our host, as to whether or not they were codes, and while answering, another member went on a belligerent rant about how they would sue me and have my board deleted if they got "hacked" from any of the features and that they would get my personal info and operation system info and I would have to give them money for a new computer.
While my staff and I calmly explained that there is no way that that could happen, and explained to them why they were amiss in their thinking, I gave them a link to the support forum where they could ask any questions they had as the support staff there was better equipped to handle them and instead of that person asking questions, they spammed and flamed both my forum and the support forum.
The entire topic became one big mess between this troll, my staff, and the owner of the host, whom, remained respectful and courteous throughout the entire time this troll was on their tirade.
What's worse, is that this person was there to fill a package request, and had even gloated about it on the ad forum they came from.. causing a bunch of that person's cheerleaders to sign up to my forum with the intention to spam.
At that point, I had anticipated this happening, (since I had been through similar with ripper and impersonators on my brother's forum, and so, I knew exactly what to do) and they were subsequently stopped by the admin approval setting I enabled for new registrations, and they were all wildcard ip banned from the forum.
I got fed up and told the person to calm the f--k down and shut the f--k up and pretty much told them why in a nutshell they were wrong with their thinking, and their behavior, and said that while I appreciate that they were coming to do the package, that I will not tolerate their rude behavior on my forum.. and that furthermore, I did not appreciate them trolling the support board as that was not the reason I gave them the link.
I went back to the ad forum in question, and received a pm saying that I had been warned. I pm'd the admin, and told them what happened, linked them to the topic, and they said I wasn't warned, and apologized for that person's behavior, and said that they had been warned and demoted. After that, I removed my profile info, posted advert, package request and my topics and posts from that site, removed the link from my bookmarks and I never went back.
If I would have known then what I know now, I would have just banned that person from the very moment they became belligerent, and proceeded to get nasty from that point on.. seeing as how they had a reputation of doing the same and were banned for it on other boards. I don't usually do this and prefer to give a person a chance.. but in this situation, I should have.
I will always remain cool in these situations and will always give people a chance, but it should be noted that not everyone can or should be reasoned with. Sometimes you simply can't expect a person to be rational, and reciprocate the courtesy in which they received.. and you just have to give the troublemaker the boot especially if, reasoning with them hasn't done any good what-so-ever.