Don't close stuff when things require answers, judge.
This one's easy.
The policy for mods that cross the line is that they are never crossing the line, unless told such by a community manager, such as Lydias or Thundergore.
They're also not required to talk to us, tell us anything, or do anything at all for us, as so lovingly highlighted by Simey, Mickster, and probably Mourhelm at one point or another that I missed.
Mods are above the rules.
They cannot be punished like other users, and are immune to infractions, and all similar things.
Basically, the whole system comes down to whether or not the mods and community managers are corrupt or not.
If you feel that a mod or community manager is doing something very, very stupid, you have two options: 1) whine a whole lot, usually over private messages to the person in question, who's going to feel so horny for power that infractions will ensue. plus the occasional stupidity from outside the forum; 2) contact Thundergore, and have him sort the mess out for you.
So far, I've had 100% success with option 2).
This option always ensures that the mod in question stops doing stupid stuff, and that repeat offenses become incredibly rare.
Do note that OMAC has a really bizarre 'you must tell no one about our secret society'-thing going on for their moderators.
You'll notice change, but you'll never know how that change came about, or what really happened, so don't waste your time asking, because the answer is always 'Xenu has not verified you as a trusted Clean. You will not be told about the volcano.'