During the 2016 campaign, Zeynep Tufekci was watching videos of Donald Trump rallies on YouTube. But then, she writes, she "noticed something peculiar. YouTube started to recommend and ‘autoplay' videos for me that featured white supremacist rants, Holocaust denials and other disturbing content.” And it wasn’t just Trump videos. Watching Hillary Clinton rallies got her "arguments about the existence of secret government agencies and allegations that the United States government was behind the attacks of Sept. 11.” Nor was it just politics. "Videos about vegetarianism led to videos about veganism. Videos about jogging led to videos about running ultramarathons." Tufekci is a New York Times columnist and a professor at the University of North Carolina. She’s also one of the clearest thinkers around on how digital platforms work, how their algorithms understand and shape our preferences, and what the consequences are for society. So as we learn that Facebook is detecting new efforts at electoral manipulation and as we watch online politics become ever more bitter and divisive, I wanted to talk with Tufekci about how digital platforms have become engines of radicalization, and what we can do about it. Recommended books: The Control Revolution by James Beniger Ruling the Waves by Debora Spar Orality and Literacy by Walter Ong  Learn more about your ad choices. Visit podcastchoices.com/adchoices