You can change the registration method in Admin Panel -> Settings -> Access from e.g. "Public - Anyone can register" to "Private - Only staff can register users" and also enable/disbale "Registration Required" there.But if you like to leave registration public, so that everyone is able to register, and you want to use the LDAP and HTTP Passthru auth plugins (like we do here) to automatically register users when they click on "Open a new ticket" etc., then I simply suggest to leave the settings as they are and do an apache / IIS redirect for the view.php to e.g. the tickets.php ;)