Finally after having problems with Spammers for quite some time, i decided to change the registration method (after asking for confirmation to Ronny Haryanto) in Indonesian Linux Forum from email (system will send a confirmation code via email and user has to open the link given) to admin (every new user must be activated by admin). This changes will make admin's work more busy, since he/she has to approve all new users, but i think this is the best for now.
For new users: If your account doesn't get approved in 1-2 days, please mail me (probably it got stuck in GMail's spam filter so it ended up in SPAM folder).
I also have added some new categories because some of the forum member request this for some time. New categories are OpenBSD, FreeBSD, and NetBSD under Unix Distribution Specific.