reCAPTCHA or anti-spam filters?

Question

For protecting my website from spam and malicious registrations/posts/etc, is it better to use something like reCAPTCHA or an anti-spam script? I was planning on implementing reCAPTCHA for user registrations on my site, using the CodeIgniter reCAPTCHA library (here). However, the CI forum on this library (here) has a lot of negative views on CAPTCHA generally that recommend alternative approaches like anti-spam scripts (e.g., sblam).

Any thoughts appreciated.

Answer 1

On a public forum I managed, the spam filter was pretty effective. The spam was typically of one kind (viagra, porn) and contained lots or links, which made it easy to detect.

However, this forum did not require registration to post. If your website requires registration, a captcha or activation e-mail will catch most of the spambots.

If your website is popular, you may get spam from humans. If this is the case, you still need a spamfilter besides your captcha system.