Web spam is on the rise, and how! Ask any person who owns a comment-enabled blog, and they’ll tell you a career of spam fighting. On a smaller scale, just check your email inbox, and you would find thousands of spam mails every week.
With spamming at such an alarming rate, it is only natural and inevitable that there will be some preventive measures. The solutions to spam are many: from word and phrase filtering (emails) to user IP detection and user ID cross-checking (blogs) to the the ever-evading CAPTCHA images (online forms).
Nothin like some CAPTCHA for breakfast, eh?
Trouble begins when they start to go overboard. As with any other thing, preventive measures against spam are getting more complex, and that is when they also start irritating users. One of those methods is CAPTCHA. Let us see Wikipedia’s definition:
A CAPTCHA is a type of challenge-response test used in computing to determine whether the user is human. “CAPTCHA” is a contrived acronym for “Completely Automated Public Turing test to tell Computers and Humans Apart”, trademarked by Carnegie Mellon University. The process involves one computer (a server) asking a user to complete a simple test which the computer is able to generate and grade, but not able to solve on its own.
A common type of CAPTCHA requires that the user type the letters of a distorted image, sometimes with the addition of an obscured sequence of letters or digits that appears on the screen.
As a side note, the troubles talked about in this post are all about the image CAPTCHAs.
CAPTCHAs were considered useful at the time of discovery, because it was thought to be fool-proof. Since the images are distorted in some way, automated bots have trouble reading them. This means that only humans can pass through. The world is saved from spam troubles, right?
You’d be so wrong.
The creators of CAPTCHAs did not take into account the human spammers, and this is one of the biggeest downfalls of such anti-spam measures. Computer literates in developing countries, armed with a computer and internet connection can be hired very cheaply, and such human spammers can pass through any CAPTCHAs.
The only things they will have to do is copy/paste the spam message into the field, enter the CAPTCHA and hit go. One more cause for headache for webmasters.
CAPTCHAs make problems when people think that more complex CAPTCHAs are the solution to preventing spam. Who knows, maybe they think the CAPTCHAs are easy and are solved by bots. So, they proceed to make more distorted images, with strike-through and other effects.
The end product of such prevention measures is that genuine users get frustrated by it, and leave. That is not a happy ending at any rate.
There is also the problem of the accessibility, as the blind cannot solve CAPTCHAs. Whatever small percentage they maybe, the internet is global, and blocking out one section, whether intentionally or not, is not correct.
The message is clear: CAPTCHAs are the inventions of the past, and are ineffective. We need better filtering methods, and some human interference for the filtering system to learn. Think Akismet.
But in the end, no amount of filtering can eliminate spam completely, and the priority should be to reduce spam to acceptable levels rather than be obsessed with spam fighting and create problems for the user.