Akismet is a spam prevention plugin from the WordPress author, Matt Mullenweg. It uses collective wisdom in filtering spams. Essentially you, blog owner, help it learn by marking comments as spam. It then uses the knowledge to filter spams from other blogs and your too. There are two major problems with this approach.

First it can be tricked. It has been shown that you can mark a legitimate commentator as spam and by repeatedly doing so you ensure that all his future comments are flagged as spam automatically by Akismet. The reverse is also true. You can manipulate Akismet to mark your spam comments as legitimate comments by repeatedly (as low as 3-4 times) marking them as non-spam in blogs you control and which uses Akismet.

Secondly Akismet can be deluged with spam to make it useless.
Akismet flags several proper comments as spam (false positives). It is essential that you sometimes visit the Akismet queue and identify the proper comments and mark them as non-spam. This helps Akismet “learn”. This however fails when Akismet catches hude volume of spam comments. It becomes impossible for humans to manually visit the queue and identify false-positives. Not to mention the current incarnation of Akismet displays only 150 comments marked as spam, with no paging capability.

This weekend I received 4378 spams! How can anyone check this volume of spam? So Akismet stops learning and becomes less useful by the day. Also some poor commentators are destined to languish in the hell of being marked as comment spammers without any hope of reprieve.

In other words spammers can render Akismet useless by simply deluging the site with large volume of spams. And it works.

In the end I think Akismet alone is clearly insufficient solution as advertised. I am hesitant to use Bad Behavior again based on my last experience where it somehow prevented several people from commenting, including my friends.

WordPress comment spam is in need of a better solution.