A special preview of the podcast, Unsung Science with David Pogue from CBS News. Journalist and author David Pogue finds the untold creation stories behind the most mind-blowing advances in science and tech—and hears from the characters involved—from their first inspiration to the times they almost gave up. This episode looks at the bad guys who used software bots to sign up for millions of fake email accounts—for sending out spam. Then, PhD student Luis Von Ahn stopped them. He invented the CAPTCHA, that website login test where you have to decipher the distorted image of a word. Or you have to find the traffic lights or fire hydrants in a grid of nine blurry photos. Those tests help to keep down the volume of spam, spyware, and misinformation; they advance the clarity of digitized books and the intelligence of self-driving cars; and, by the way, they made a handsome profit. The only problem: We HATE those tests! Guest: Luis Von Ahn, co-inventor of CAPTCHA, co-inventor and CEO of Duolingo. Hear more episodes of Unsung Science at https://unsungscience.com/.