Luis von Ahn the founder of the company reCAPTCHA, which was sold to Google in 2009, and the co-founder and CEO of Duolingo, the world’s most popular language-learning platform.
Luis came up with CAPTCHA when Yahoo Mail needed a way to combat bots creating emails. Yahoo approached Luis and he came up with text that a human can read it but a computer cannot, which is called Captcha.
Luis also provided services to digitize old books that computers couldn’t recognize. So he used those hard to read books and use them as CAPTCHA. 120-125 million books a day is being digitized a day. Not only books were being transcribed, but old New York Times articles are being digitized.
Google bought out Luis’s technology for an unknown amount.