[duped]

Having a CoC is what gives moderators of a community the ability to drop the ban hammer and give a decent reason (in other words, establish some rules and keep out people who routinely break them). Enforcement is rarely public, for the same reason you don't fire someone in front of the entire office.

[Cthulhu_]

I mean CoC violations can also result in people losing their jobs; it's better to handle things in private. That also removes any cool factor from someone who's blatantly being a troll, the "us vs them" mentality that's easy to pick up.