Defensio: Outsmarting Evil Spam

Yes, Defensio's web service combined with the any of the plug-ins we provide are intended to replace Akismet as your blog's (or application's) shield against comment spam.

Well, it depends on your blogging platform. Instructions are provided alongside each of the plug-ins that can be downloaded here. Don't forget to sign up for an API key. You'll need one in order to use Defensio. (it's free.)

We can't make any promises (sorry), but our early testing suggests that Defensio's performance is very, very good. As with any adaptive filter, it will only improve with time. You may need to give it a few days before it really kicks into gear, but quite quickly you should see a significant reduction in the flow of comment spam to your blog.

If you have recently installed Defensio, then try to be patient. The filter's learning algorithms take some time (usually no more than a couple weeks) to become very effective, so in the early days of installing the filter performance might not be what you'd hope for. Alternatively, if your blog receives a low amount of spam (say less than 100 comments per week) Defensio will have a smaller sample set to draw from, and may not perform to expected levels. But if you've had Defensio running for some time and you receive healthy comment traffic, and filter accuracy is still sub-par - then please shoot us an email, we'd love to take a look.

Importantly, make sure you correct the filter when it has gone astray. Restoring good comments that were incorrectly marked as spam, and marking errant spam as such will help the filter learn -- in a personalized way -- your own spam fighting habits. Moreover, if you do not agree with a comment but it is not spam per se, make sure to delete it instead of marking it as spam.

Recent accuracy is a measure of how well Defensio has been performing on your blog lately. It is computed by subtracting out the errors (false postives and false negatives) over the last 7 days of comment activity on your blog, and dividing this by the total comment traffic over that period. The closer Defensio is to 100%, the better we're doing!

Not really. We highly recommend that you use Defensio as your stand alone spam filtering solution. Other spam plug-ins will only serve to lessen the opportunity that Defensio would otherwise have to get to understand your blog's spam traffic.

The spaminess of any comment is mathematically computed taking into account all its features, and represents the relative likelihood that it is spam. Lower spaminess values indicate a lower chance of the comment being spam. High spaminess suggests a comment is very likely spam.

If you're spam comment volume has been seemingly turned off completely since installing Defensio, please check your Defensio configuration options to see if you haven't inadvertently selected the option that automatically deletes spam on posts older than X days. With this option enabled, you can very well expect to see only a fraction of the spam that used to come in. Otherwise, you should continue to see a similar number of total spam (but hopefully less squeaks through to your site!)

Yes, for all personal bloggers. We do however have commercial use plans, which you can read about here.

While at launch we’ll only be making available a WordPress plug-in, many developers from around the world are busy building plug-ins and applications for the Defensio platform as we speak. These will be posted to our Downloads page as they are made available. Subscribe to our RSS feed to be kept in the loop.

Defensio is more than just a blog spam filter, but a spam filtering service for any social web applications where spam might be an issue. We expose a public API that you can easily leverage for your own applications -- in fact, many developers already have. Head on over to our API page to learn more about it!

In order for our plug-in to work with your blog, we need to generate for you a unique API key. This requires some personal information (namely your blog and email address), and thus the requirement to create an account and sign-up for the service. All personal data will be kept strictly confidential, as described in our Privacy Policy.

It’s true, we’re intentionally unspecific about the underlying technologies and methodologies we’re using to fight spam. It's not that we're uncomfortable with disclosure, nor that we lack confidence in the strength of our filter; but rather, we believe it's in our collective interests to keep the spammers guessing as much as possible (they are, after all, reading this site along side good people like yourself).

We don't actively chase down spammers, but instead take the pragmatist's attitude that since spam is and will continue to be a problem, we need the best tools possible to manage it, that is, prevent it from ever getting to your blog. If spam never made it through, spammers would be out of business.

Defensio is developed by Karabunga Inc., a web development shop which operates out of a old tobacco factory just outside of Montreal, Canada.