static function countContentObjectByEmail( $email, $status = false )
    {
        $statusString = "";
        if ( $status !== false )
        {
            $statusString = " AND status = $status";
        }
        $sql = "SELECT COUNT(*) as row_count FROM " .
               "( SELECT DISTINCT contentobject_id, language_id ".
               " FROM ezcomment " .
               " WHERE email='$email'" .
               "$statusString" .
               ") as contentobject";
        $db = eZDB::instance();
        $result = $db->arrayQuery( $sql );
        return $result[0]['row_count'];
    }