That's the purpose of the admin setting.

I have a mysql-backend address book called "My address book".Strange 
thing is administrator can view all contacts of this book in browse 
view,even contacts were created by other user.



Here are partial turba/config/source.php for your information.

==============================================================

$cfgSources['localsql'] = array(

     'title' => _("My Addressbook"),

     'type' => 'sql',

     'params' => array_merge($conf['sql'], array('table' => 'turba_objects')),



         'map' => array(

         '__key' => 'object_id',

         '__owner' => 'owner_id',

         '__type' => 'object_type',

         '__members' => 'object_members',

         'name' => 'object_name',

         'email' => 'object_email',

         'alias' => 'object_alias',

         'homeAddress' => 'object_homeaddress',

         'workAddress' => 'object_workaddress',

         'homePhone' => 'object_homephone',

         'workPhone' => 'object_workphone',

         'cellPhone' => 'object_cellphone',

         'fax' => 'object_fax',

         'title' => 'object_title',

         'company' => 'object_company',

         'notes' => 'object_notes',

         'pgpPublicKey' => 'object_pgppublickey',

         'smimePublicKey' => 'object_smimepublickey',

         'freebusyUrl' => 'object_freebusyurl'

     ),

     'search' => array(

         'name',

         'email'

     ),

     'strict' => array(

         'object_id',

         'owner_id',

         'object_type',

     ),

     'public' => false,

     'readonly' => false,

     'admin' => array('administrator@tmv.gov.tw'),

     'export' => true

);