October 20, 2007
reCAPTCHA: Stop Spam. Read Books. Do Good.
Many sites use CAPTCHA mechanisms to secure comments and forums or access to certain features. Sadly necessary to prevent automated attacks and bot spamming, purportedly 60 million CAPTCHAS are solved daily. If we assume 10 seconds per, that represents 150,000 hours of human time wasted each day.
Carnegie Mellon's School of Computer Science realized they could reclaim that wasted time and put it to good use with reCAPTCHA, a free CAPTCHA web service that instead of presenting randomly selected letter/number sequences to solve, serves words from book scanning projects that failed OCR, thus lowering the cost of book digitization and preservation at the Internet Archive.
This is a brilliant leveraging of network effects for the common good.
I've implemented Josh Carter's reCAPTCHA plug-in for Movable Type -- take a look at the comments to see how it works. For this site I've chosen the 'blackglass' theme with some added CSS so that the input field uses my type style. You can also select from red and white themes, or elect to create your own styling on a 'clean' theme.Posted by Lewis Francis at October 20, 2007 7:15 PM