PHP Screencast: Hidden Captcha
As I was saying in a past–not so documented–article, this is how the Hidden Captcha concept works:
If yes, they’re okay — let’em comment, no annoying captcha required.
No? We’ve got a suspect. Read them their rights and serve them the ultimate “are you human?” test.
Here’s what you start with, the source code from this tutorial.
(Note: be sure to have the Arial font file called arial.ttf in the fonts folder–copy it from your System in there because their archive does not come with it).
<div id="captcha"> <img src="captcha.php" alt="" /><input type="text" name="code" /> Are you human? </div>
Hidden Captcha instead of Akismet?
Since I’ve installed Simple Captcha, the Akismet spam count remained at 0 (zero).
And this leads me to the Akismet false positives issue. Where innocent comments can sometimes incorrectly show up as spam and get lost in the thousands of real spam comments.
How Spammers can play with Akismet system and get you banned?
Lets take an example of a blogger who wrote a harsh comment on other blogger’s website. Now the other blogger will take his identity (username, email and URL) and put them into a spam script (believe me there are plenty out there) and he will set the script to send out 100’s of comments/trackbacks to other blogs. Of course, most of these blog owners who got the ’spam’ would flag these comments as spam. This would result in your credentials being incorrectly marked as spam comments by hundreds of bloggers, thus ruining your expertise to promote your site.
You can read the rest of that article on Mind Tree.
Akismet is great and all, but man… I don’t want to send innocent people to the spam box.
So this Hidden Captcha system (easily implementable on any existing captcha system as seen in the screencast) can actually allow me to disable Akismet (thus eliminating the possibility of false positives) and keep actual spam comments away.
No usability issues because of hard to read captchas–for most of the readers.