SpamDog

First or later any website administrator have to combat this war, especially when your site starts to be a little bit more popular. Tipically the most common spam target at your site are:

Registration Spam
This is one of the most common target of Spam that you might see on a typical Joomla site. I have seen tons of fake accounts this happening both by automated scripts as well as human

Forum Spam
If you have a forum on your site you are a target for this kind of Spam. This typically contains ads text and links.

Comments Spam
If you have a comments system to allow users to post comments on articles you are a target for this kind of Spam. This typically contains ads text and links.

Contact Spam
If you use Contact the email account are a target for kind of Spam

The SpamDog give you some weapon to fight Spam:

Passive weapon

Whenever a content or registration is sumbitted is first evaluated by specialized webservices like:ProjectHoneypot, StopForumSpam, FSpamlist, BotScout, Akismet, Mollom, Defensio, and some RBL

and only after an “ham” classification are allowed.

Active weapon

These webservices databases are updated continuosly so maybe the spammer could be trapped some days later