reCAPTCHA: More than the Usual Anti-Spam Measure

It started with junk mail in real life, creeped into our virtual mailboxes, and has now invaded our blogs as comments and trackbacks. Blog spam is usually characterized by generic advertisements for silly stuff including but not limited to porn, warez, lotteries, pills, insurance, and real estate—often with a suspicious-looking URL.

You start getting spammed when spambots find your blog. Unfortunately, that’s the price you have to pay for being “popular.” The good news is, many developers have thought of ways to combat comment spam. Perhaps the most famous right now is Akismet, which has the following Spam Zeitgeist this very moment:

1,627,765,499 spams caught so far
10,709,505 so far today
95% of all comments are spam

Akismet is an automated way of detecting spam comments with a super-secret algorithm. reCAPTCHA is also automated, but is based on CAPTCHA (Completely Automated Public Turing-Test to Tell Computers and Humans Apart), which only allows comments to be posted when a user overcomes the challenge. The challenge posed by reCAPTCHA is to type in two distorted words which are actually scanned texts from books.

reCAPTCHA: More than the Usual Anti-Spam Measure

The purpose of reCAPTCHA becomes two-fold: first, to combat spam on the blog where the reCAPTCHA plugin is installed (since computers are supposed to fail CAPTCHAs); and second, to convert printed words into digital ones with the help of humans (since they are better at it than computers).

People are pretty much divided on the use of CAPTCHA. Some people hate the thought of having to enter text into an additional field just to comment, some argue against its accessibility issues, while others gladly “welcome the challenge.” Although CAPTCHA in general may not be the only or perfect shield against spam, reCAPTCHA might interest you for an even nobler intent.

reCAPTCHA is available for WordPress, MediaWiki, phpBB, MovableType, Symfony, Typo3, NucleusCMS as well as in general PHP, Python, Perl, Ruby. Finally, you can also use it as a tool to hide your email address from spammers.