Todd Lahman's comment spam blocking plugin that blocks automated spam with zero false positives.
I believe I was using this plugin from the early days of it. Then I rated it 5 stars. At this time, maximum I can give - 2 stars.
Please understand, that these ratings are not for the commercial "pro" version. We should rate plugin that is hosted here and it is not stellar anymore.
I've used this plugin since its early versions and although it needed some tweaking with almost every release to make it compatible with certain WP theme forms, it performed its spam filtration very well.
When version 2.0 was released, I did not update it after seeing the reference to the removal of the free license. With 2.0, the previous version, 1.9.3, had several of its options removed; supposedly, it works the same out of the box, while the author promotes his commercial alternative. As far as I'm concerned, 2.0 downgrades the effectiveness of the free plugin.
After keeping 1.9.3 as the active version, I am now getting lots of spam that is caught only because Akismet is installed. I'm suspecting that the license key mechanism used in versions prior to 2.0 is now broken, allowing spam comments to get through.
This plugin is currently a shadow of its former glory. I tried to be as objective as possible; for active blogs and publications, spam prevention is essential.
I tried and tried to get this plugin to work for me with no success. I believe I had it set up and registered properly, but saw no change in the number of spam comments I received.