static function create($firstname, $name, $mobile, $email)
 {
     if (!$email) {
         return false;
     }
     $rows = array('firstname' => $firstname, 'name' => $name, 'mobile' => $mobile, 'email' => $email, 'hash' => md5(time() . '-' . mt_rand()));
     $userData = new eZUserSubscriptionData($rows);
     $userData->store();
     return $userData;
 }