Like all bloggers, I find comment spam to be a constant annoyance. There are many ways to mitigate the problems it causes however and using the following techniques means that this site is subject to almost no comment spam.
Use WordPress’ built in comment spam tools –
- In WordPress Options -> Discussion, fill in the list of common spam words – words in this list automatically cause a comment to go into the moderation queue. I use the following list.
- Also use the Comment Blacklist field. Populate this very carefully. Any comment containing words in this list are nuked automatically. No notification. No way to get them back. Gone. This is the list of words I have in my blacklist.
- I have checked the “Comment author must have a previously approved comment” field as well. This is a very simple but very effective tool – regular commenter’s are able to leave comments and see them appear instantly; new commenter’s comments are held for approval and if they are not spam, their comment appears in short order and subsequent comments appear immediately.
- And I use WordPress’ built in anti-spam plugin – Akismet.
I also have a custom .htaccess file which stops a lot of spamers cold before they reach the site at all. Excercise extreme caution with .htaccess files as they can take your entire site down. If you are not sure what you are doing, I have written a few explanatory articles on .htaccess files previously. If you are still not sure what you are doing, put the .htaccess file down and walk away very slowly!!!
Finally, I use plugins called Referrer Karma and Bad Behaviour which help significantly by stopping bots from accessing your site to leave comment spam.
Having implemented these techniques ensures that my site stays free of comment spam without having to moderate all comments and without having to implement CAPTCHAs. CAPTCHAs are those horrible badly drawn images of combinations of letters and numbers which some people put on their sites to stop spam. CAPTCHA’s are evil*. Stop using them. Now.
* The American Foundation for the blind has written many times about how difficult Captchas make browsing for blind or partially sighted people and the W3C in a report on Captchaâ€™s said:
A common method of limiting access to services made available over the Web is visual verification of a bitmapped image. This presents a major problem to users who are blind, have low vision, or have a learning disability such as dyslexia.