I activated the “captcha” feature a few days ago--requiring registrants to type in a visually presented sequence of characters. It seems to be working well--it’s cut the number of spammers who make it to the “pending” stage (i.e., awaiting a reply to the email) to effectively zero. Yesterday, however, one did make it through all the way to post some spam on the forum. So it’s not 100%.
It’s too early to tell if it will actually reduce the number of spammers that actually get through--the number before was too low to notice a difference in just a few days. But it will reduce my workload of deleting old pending registrations (and will eliminate the bounced emails that tell me that the registration email was not accepted). So I will probably keep the captcha feature in any case.
(FYI, the most ingenious way that I’ve heard of spammers getting around captcha was to set up free porn sites that require a user to enter a captcha form to log on. They then feed the human porn-surfer a captcha string from a site they want to spam, and the human porn-surfer reads the characters and enters the text--sticking an unwitting human porn-surfer into the automated loop to get around the visual obstacle.)
I’ve looked at the Akismet plug-in, but that seems to be primarily for comments to the blog posts (Big List and Harmless Drudge posts). I killed the comment feature a few months back not only because of spam, but also because the non-spam was almost 100% disinformational, people posting half-baked or no-baked theories about etymology or asking questions that were answered in the entry they were commenting on. (I can only recall one comment that actually provided useful information--information I eventually incorporated into the Big List entry itself.) Even discounting spam, the signal-to-noise ratio was extremely low. Plus the total number of comments was not large--it was not a popular feature overall. Unless the plug-in can also help on the discussion forums, I don’t see that it’s worth it to reactivate the comments feature. If there were a low-level of intelligent and active commenting on the Big List and Harmless Drudge posts, I would put up with the effort to deter spammers, but I can’t see doing the work for a feature that isn’t really being used.