From a discussion where Wikipedia admin Durova, proposes a formal process to re-integrate banned contributors.

From the comments area, by Gregory Koh:

“There are, very generally speaking, three kinds of people who get “sitebanned” from WP:

Spammers, haters, and people who simply believe they’re right about something (or that someone else is wrong) and are unwilling to simply accept defeat. The first group (spammers) are usually banned fairly readily and should stay that way; the second (haters) are often not banned at all, though they usually should be. The third group is where most of the unfair/unjust bans come from.

The secret to winning Wikipedia: The Game is to convince others (especially admins) that someone who disagrees with you, but is otherwise relatively harmless, is actually either a spammer or hater.

These things have little to do with someone’s “failure to understand the rules.” They have everything to do with politics, personal alliances, refusal to compromise, wearing down opponents with ceaseless bickering, and so on.

Wikipedia can do nothing about this, at least not without external governance or professional peer review. It’s endemic to the system, and this talk of “mentorship” and “contrition” is really just a waste of bandwidth, not to mention insulting to people who have clearly been wronged – at least as long as the current conditions are in place.”