[CalendarServer-users] shared addressbook

Hello calendarserver community, I'am completely new to calendarserver and try to get calendarserver (3.2) up and running on Debian (7.5). I would like to configure an shared address book. If I figured it out correctly address books can only be assigned to users and not to groups. Therefore I set up an user (user1) and created a few contacts. Now I would like to share this address book with other users. Thus I created a group with all users. It looks like calendarserver_manage_principals --add-write-proxy has no effect on this. For calendar's, on the other hand, it works great. Am I doing something wrong? Is there a solution for this except everybody uses user1's login and password? thanks in advance bodo