But sometimes it won't work that way. It becomes clear to the members that a person spells "trouble" in one way or other. In this case he may become an UnwelcomeVisitor. The typical situation is disrespect to the expectations defined in VisitorRole / GuestRole and unwillingness to learn from the hints of other members.
There is no clear precedence how a person is made an UnwelcomeVisitor. I would suggest that a number of members should declare him as "not welcome" on his homepage and form a common RequestToLeave. So it would work like the reverse of WelcomeNewcomer.
A visitor or guest may break expectations by being not peaceful, or if he assumes the CommunityMember role prematurely. It is common that we have to explain why people have different rights. It's not always the case that members have more rights, sometimes they have less. For example we are more tolerant towards guests with respect to off topic content than towards members. We do expect that members don't offend people, because this may damage the reputation of the community. -- HelmutLeitner