DDos Protection/Captcha for Guests

[Maxtor]

Who can make this mod example , and block all guests from viewing any page in forum.
Only members will be able to view forum.

- Guests will view only the example.
- block all guests from all links in entire forum . they will see only example.
- (optional) block after 3 failed attempts for x seconds.
- (optional) option to allow google bot .


I need to block this attack. http://i42.tinypic.com/jtxj0l.png