Just came to my fórum and click on register (torne-se um novo membro). http://www.forumdepizzarias.com
It asks to write the pasword 9521 but "backwords"
If you try another number, a message apears.
Its really simple to do by creating a new field registration that do not accept any other value but 1259 (or any ohter number you like)
captcha wasn't working (i'm thinking about test disable captcha)
and If a guest tries to post, apears a message giving the username CONVIDADO and a password to login and post 'anonymous' (as CONVIDADO, off course)
CONVIDADO is brazilian portuguese for GUEST
PS: At the first day we has a lot of bots on 'register' page, but none register.