User blog comment:Ducksoup/Why We Don't Unblock You/@comment-26009167-20150916211911/@comment-25035274-20150917131846

Admins already 'can' block you for varying length of time, setting it to automatically reinstate your account once that time has passed. Different wikis have different admins/owners, however, and those admins/owners lay down different rules for their wikis. Where one wiki might give you a "three strikes and you're out" policy (my community does admin warning, 3-day susp, week susp, permaban; with a few certain offenses being an immediate permaban first offense), another might opt for a more direct "You done messed up, Son" approach and permaban you on the spot regardless of what the breach was.

Ideally, any given community should have its rules (or a link there-to) posted somewhere publicly visible (front page's the best spot). These rules should state the expected conduct of users/members, and the disciplinary structure. If more Wikia communities did this, it'd eliminate a lot of the headaches staff get from having people whining, "But it's so unfaaaaaiiiiiiiir!!!"