Fighting Comment Spam on the Cheap with CAPTCHA
Richard L. Apodaca · 2007
If you run a blog or website that allows public input, you've almost certainly been subjected to a spam attack. This is a problem because even one successful attack can eat up hours of time. After a recent spam attack on this blog, comments were disabled altogether. They've now been restored with the help of a more robust kind of protection, which is the subject of this article.