When groups are added to Beaker it is not clear who is the "Owner" of the group. I would help if there was a way to set a Group Owner. So when an RT is submitted to add a person to a group the Owner of the group can be asked if it is ok.
For Beaker 1.0, we will be implementing an Enhanced User Groups model which addresses this problem in a slightly different way (see http://beaker-project.org/dev/proposals/enhanced-user-groups.html). *** This bug has been marked as a duplicate of bug 908174 ***