alban, please stop responding to non-constructive comments, that's just going to fan the flames.
I've skimmed most of these responses and they all seem to be similar things. Here's some of that constructive criticism you are after.
People would be more accepting of, and greater served by a "network of trust" style list.
Let people have their own ban-lists and let people add each other as friends with a percentage figure that represents complete trust to no trust.
When presenting a ban list to a signed on user, form a list of all the ban's in their trust network and cull anything that's under a certain threshold (let the users configure that threshold).
I have Frogboy on my list with a trust of .8
Frogboy has ToadWoman on his list with a trust of .5
Toad Woman has banned CylonLoveSlave
that ban has .5 of frogboy's .8 which is a ban threshold of .4
To further complicate things, lets say I also have AngstyGothErebus on my list at .2, he has also banned CylonLoveSlave. CylonLoveSlave now has a ban threshold of .6 and when I see him in the list I should be able to drill down to a list of who has banned him, what for, and what threshold I'm getting from that person... Maybe even the chain that leads me to that ban listing.
That system is more or less griefer proof as you're only looking at who's pissed you or your friends off, and once you make a few good friends in the community you'll have a pretty big friend network (look at facebook and friendster to see how that works)
As for ban resolution, allow people to put their "in game names" into their accounts. When a ban is added, if it matches an existing account, let the banner decide whether to notify the doucherag or not and give some sort of PM functionality for the two users to communicate in case there's a misunderstanding in which case the banner can elect to remove the ban.
Such a system will be a bit more work for you, but it'll provide a lot more value and will probably be interesting to build and analyse