How to restrict BlackBerry users to see the other GAL users

Hi Everyone,

I have a blackBerry Enterprise server and couple of blackberry users.
To add a user to the BES it needs to be in GAL.
But the blackberry users are able to see all the users present in that
GAL, but I want to restrict it and do not want to allow the users to
see the other users in GAL. Can anyone help me out in this matter.
Will appreciate your help.
Thank you

Regards,
Viren