Currently Second Life has options for banning individual avatars from land, and even from individual privately owned parcels, but there is no similar option for group. Take a large group that is open in membership because it's intended to be a social group. It is impractical to close membership just because of a few griefers, but although you can eject an avatar from a group if the group is open that avatar can immediately rejoin. It would be useful to have a banlist function on group membership so that people who are being disruptive in a way that doesn't break the ToS can be prevented from causing trouble, or from rejoining a group in order to build on land that is group-only build.