Has there been any discussion on this matter? If a user is being disruptive on a wiki he or she will eventually end up getting blocked for it. If the same user decides to continue this disruption he was blocked for on other wikis, particularly sister projects, commons, meta and etc how should he or she be treated. I know every wiki is independent. But letting a disruptive user become the source of agony on many wikis seems like a problematic thing to do. - White Cat