For questions about the reCAPTCHA service: Designed to protect against spam and abuse by blocking bots while allowing valid users access.
reCAPTCHA is a system originally developed at Carnegie Mellon University that uses CAPTCHA to help digitize the text of books while protecting websites from bots attempting to access restricted areas.
reCAPTCHA requires a user to select images which do or don't include certain items in them. The technology works due the ability of a human being to distinguish subtle visual hints that AI would not yet recognize.
On September 16, 2009, Google acquired reCAPTCHA.
