Web Security Words Help Digitize Old Books
From All Things Considered:
People who use the Internet to talk to friends, set up free e-mail accounts or buy concert tickets are often unknowingly helping to digitize vast libraries of old books and newspapers.That's because more than 40,000 Web sites — including popular ones such as Ticketmaster, Facebook and Craigslist — are using a new kind of security program called reCAPTCHA.