This plugin has been closed as of 04 November 2022 and is not available for download. This closure is temporary, pending a full review.
Running WP 6.0 now. Error raised today: An error of type E_ERROR was caused in line 34 of the file /home/*/blog/wp-content/plugins/bad-behavior/bad-behavior/banned.inc.php. Error message: Uncaught TypeError: dechex(): Argument #1 ($num) must be of type int, string given in /home/*/blog/wp-content/plugins/bad-behavior/bad-behavior/banned.inc.php:34 Looks like it chokes on IPv6 addresses. As a consequence, I disable and deinstall now the abandoned plugin.
I've given this plugin various opportunities throughout my decade of using Wordpress, and while it does work to filter out spam comments for the most part, so do a lot of other plugins. If it wanted to stand out, it needs to not cause problems with my websites themselves. Unfortunately, it's come to my attention that it's not working friendly with PHP version 7.2 which is what my hosting service is recommending me to use at this time. If a plugin is not keeping up to date with basic PHP versioning and giving my site loading problems, I'd be better off with other solutions.
Although sometimes it can be tricky if you get a false positive, those are pretty rare (haven't seen one in a couple years). Works well to keep bad actors off your site.
Disconnects MWP irrevocably.
I was using Bad Behavior and suddenly my iThemes Sync plugin locked me out of 7 websites. Bad news. After much troubleshooting, I had to log in to all sites individually to whitelist the ips. Don't know why this happened overnight and to all the websites, but if such behavior continues I will have to uninstall Bad Behavior.
This has been a "Must have" on every site I build. It cooperates with every plugin that I have used for years and simply works. No fuss at all no conflicts and so easy to set up.