Heavy-duty CAPTCHA

Posted by Chris Green on Monday July 9 @ 10:37 pm

I’ve been using the Askimet comment spam filter on this blog for well over a year now, and its just as well that I am as to date it has trapped a whopping 35,814 pieces of spam. The number of items that have sneaked through are so few and far between, it barely registers – we are talking about less than 100 items since I started using it, and all of those were intercepted by moderation, ensuring that not a single piece of blog comment spam has seen the light of day here.

However, the onslaught of comment spam is getting bigger, and I’ve decided that Askimet needs some backup. So, I’ve now implemented some heavy-duty CAPTCHA technolog. A CAPTCHA is a program that can tell whether its user is a human or a computer. You’ve probably seen them — colorful images with distorted text at the bottom of web registration forms and blog comment pages. CAPTCHAs are used by many websites to prevent abuse from “bots,” or automated programs usually written to generate spam. No computer program can read distorted text as well as humans can, so bots cannot navigate sites protected by CAPTCHAs.

I’m using reCAPTCHA, and in order to post a comment from now on, you’ll also need to key in both the words shown in the graphical display (with a space between them, as if you were typing two words normally) to prove you are you, and not a bot, or some comment-spamming cretin from a third world hole in the Earth. You can ask for a fresh image if the one you are presented with is too mangled, or even an audio prompt instead of the graphic.

One response to “Heavy-duty CAPTCHA”

  1. Confused of Central London says:

    Argh! The voices! Make it stop!

    Dude, the audio version is completely unintelligible. And if you had the slightest thing wrong with your eyesight, you’d never find the audio button anyway, especially as it keeps fighting with the almost equally irritating Snap Shots pop-up!

    CAPTCHA is a hateful thing that discriminates against a wide section of the audience – especially those of us who read stuff on mobile devices. From your post you hardly get any spam which isn’t already trapped by the excellent Askimet filter, turn this thing off and let us post from whatever comes to hand again!

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