On a couple of occasions I've seen users be voted off of private instances by either a raiding group or a crowd that disagreed with the owner's decision to invite a certain person. Instance owners ideally should have some form of total control over who is in their spaces, and this goes in both directions... it's already the case that an owner can kick without needing a vote, but they're unable to stop a kick from happening if they disagree with the crowd's reasoning behind it.