Around the time you finish setting up your WordPress blog—or not until a day or two later, if you’re lucky—you’ll start getting “comment spam.” Comment spam is a stream of mostly nonsensical comments left on your blog in the hope of routing traffic to the spammers’ target sites. The comments contain links to those sites. They’re counting on finding blogs on which comments aren’t moderated, leave their links, and drive up their own search engine rankings. Most of the spammers seem to employ software robots to drop their loads of unwanted canned meat in your comment threads. But there are also humans who engage in this tacky form of self‑promotion, plugging their porn sites on your blog about needlepoint, for instance. (Posting legitimate, relevant comments with backlinks to a site about a related topic, on the other hand, is perfectly cool.)

Fortunately, WordPress comes loaded with a strong defense against comment spam …[more]