def getGroupedUsers(self, groups=None):
        """ Retrieve all users that in the groups i know about """
        all_dns = {}
        users = []
        luf = self.getLUF()
        possible_members = GROUP_MEMBER_MAP.values()

        if groups is None:
            groups = self.getGroups()

        for group_id, group_dn in groups:
            group_details = self.getGroupDetails(group_id)

            for attribute_name, dn_list in group_details:
                if attribute_name in possible_members:
                    for dn in dn_list:
                        all_dns[dn] = 1

        for dn in all_dns.keys():
            user = luf.getUserByDN(dn)

            if user is not None:
                users.append(user.__of__(self))

        return tuple(users)