The Underground CAPTCHA Industry


Humans can solve them, computers cannot, or so we've been led to believe. Yes, I'm talking about CAPTCHAs, those annoying puzzles you see whenever you post something to Craigslist, or even try to leave a comment on this blog. Originally designed to block spam, Completely Automated Public Turing Test To Tell Computers and Humans Apart, or CAPTCHAs, come in handy in protecting Web sites against bots.

As of this year, 90 percent of e-mail traffic is spam. So anything that helps stop spammers is good, right? Perhaps.

CAPTCHAs have given way to an underground industry booming in places like India, Bangladesh, Pakistan, China, Brazil, Nigeria, and Russia, where scores of people are hired to solve these Captcha and, subsequently, flood the internet with even more spam. These people work for embarrassingly low wages, practically pennies— in return for doing tedious work.

Web sites like India-based, offer a "do-it-yourself" guide to solving CAPTCHAs. In theory, these guides could be used by CAPTCHA organizations to train their employees, as well. The site offers $2 for every 1,000 CAPTCHAs solved. Those who register with the site only pay for CAPTCHAs that are correctly decoded.

sample-ocr /

There's a company in Delhi, India, that calls itself the "Ccapt Team." They look for individuals to do CAPTCHA data entry and claim to pay, on a weekly basis, $1 for every 1,000 Captcha entries.

CAPTCHA companies have created many ads all over the internet. The ads serve as the primary tool used to recruit their workers. In one example, an ad asks for long-term CAPTCHA work, requesting only large teams that will work from 4 p.m. to 11 a.m. (India Standard Time). They are looking for employees who can work from their homes in India, Sri Lanka or the Philippines. The terms also require that they are professionals or able to work part-time.

Another company 's ad lists several "rules and regulations" necessary for successful employment. They include: a "1 day trial work for eligibility." The other requirements consist of an invitation for "serious" bidders to bid due to the fact it is a long-term project. Twice-weekly payments are promised.

Many of these CAPTCHA solvers make much more money than they do at their legal data-processing 'day jobs.

Dr. Luis Von Ahn, who helped create CAPTCHA nine years ago at Carnegie Mellon University, calls such companies "Captcha Sweatshops." Of course, not every CAPTCHA-solving organization is designed for malicious purposes. For instance, there's the American-based site called whose goal is to automatically translate CAPTCHA images into simple text for the purpose of helping the one million blind people who live in the United States. Screen reading software would read the text for them, so the blind would be able to understand each CAPTCHA image.

And on this blog, we use reCAPTCHA, a service that helps to digitize books, newspapers and old time radio shows. By offering up words that cannot be read by computers to you, the CAPTCHA solvers, each correct match feeds the database and helps the computer learn.

The only other thing I've got to say on the subject is this: who started the trend of noting interesting CAPTCHAs, or ironic CAPTCHAs (vis-à-vis a blog post, let's say) in the comments?

Would be amazing to find the very first instance.

Until then, CAPTCHyA on the flip side. (Sorry! I'd been waiting all post to write it"¦)