I've posted again in this discussion. For me the ultimate example of quite and peaceful forum is a Greek one, ( same subject is about cycling) were there is no moderation at all. The only thing that moderators do is to delete unwanted spam messages, like ads etc.
No bans, no warnings, no word filter nothing at all.
The other day, a guy, who is well known now in the forum members as troll, opened a new topic with the provocative tittle "All leftists are idiots and stupid".
What it followed, against his expectations, was a very polite and civilized discussion about political and philosophical things. In the end the troll-member asked if for gods shake is any kind of moderation in this forum, to ban those who extended his topic in such philosophical way..(you see they totally "ruined" his discussion or what he expected from this discussion

)
20.000 members in this forum and only 3 identified as trolls. Two of them with political obsessions ( one far left and one far right who usually fight in their own threads and nobody bothers them) and one totally stupid and rather insane that now has the role of the clown in the site and people like him because nobody takes seriously his posts and don't bother to reply seriously to him.
We don't ban trolls because then will come back and we will not know who is who. We keep their accounts active and we know what to expect from their posts.. Simpler.