CAPTCHAs have been the subjects to extremes – hate and love, complete discard and tremendous reliance on the Web to avoid spam. They are instrumental in identifying humans from machines that programmatically send spam messages. They have been effective, but with a big problem. They are inaccessible which means that some humans, including the ones that disable images in their browsers, might not be able to read them making them hindrances instead of gatekeepers.
Alternatives have been suggested, with a common thread to make it accessible by using text and simple logic instead of images.
There is a new kid in the town – reCaptcha. It is CAPTCHA with a noble cause, the phrases presented to users are obscure texts obtained through exercises of digitizing old books. Users, through solving CAPTCHAs, help in making these clearer. It is the idea of employing a huge distributed power to solve a big problem, similar to the Chinese Lottery (via ha.ckers.org).
I think the idea is good, it is nobler to use the reCAPTCHAs if you are already using CAPTCHAs. But the basic inaccessibility and onus on the user to identify self as a human is still a problem which can lockout some users. Additionally CAPTCHAs fail if humans and not bots are used for spamming. I still consider Akismet to be a better solution. Akismet uses the community to identify spam without putting an extra load on the user.
