Contacting people over matters in AB to harass/attack them IS NOT ALLOWED.
Just because someone has broken a rule, that does not make it okay to insult or pester them. Especially because doing so means you've broken a rule yourself. And yes, this rule applies to PMs/emails/whatever. If it spawned from AB, don't go after them.
2. Whatever happens in the community, stays within the community. Do not go to the offender's LJ or art site account and harass them, or contact them any other way if the matter under discussion does not regard you personally.
Mods are here for a reason. If someone messes up, we tell them. We don't need you guys going and attacking them. It is not acceptable by any means and WILL get you in trouble if we find out you've done it. You should also know better, as a group consisting mostly of reasonable adults. Banned/warned members are not 'free game'.
TL;DR, don't harass people over things in the community. You WILL be warned or banned for such.