Captchabot.com is a service that automates the solving of CAPTCHAs, those annoying agglomerations of squiggly numbers and letters that many online services require users to solve. The service claims at least an 80 percent success rate, and customers only pay for CAPTCHA that are solved correctly. The majority of the workers employed by the service live in Belarus, the owner of the service says, “They using it for legal Webspam, like blog comments””]
Source: https://krebsonsecurity.com/2010/11/captchabot-blurring-human-and-machine/