OK, that gives some insight, thanks!

I participate in three other forums online. One is a sailing forum which is totally out of control and incredibly rude, juvenile and obnoxious....and massively popular... I don't spend much time there any more. I moderate another sailing forum which is not terribly busy, though we have about 120 members and in the past three-four months I've had to delete one post. Finally I participate in another forum which is definitely NOT family-friendly and while sometimes the posts get pretty edgy, the participants seem to more-or-less police themselves. When the option to post anonymously was removed, nearly all the obnoxious behavior vanished.

So those are my points of comparison. Thanks again for the insights into keeping an eye on X-Marks!