Reid Brown remembers the first time he got sucked in by the algorithm — he was just 13, watching videos after school when YouTube started pushing him to controversial content. As time went on, the videos became increasingly extreme, says Brown, now 21. "It started out pretty benign," he recalls. "You're watching something about teen fashion and then the next thing you know, the algorithm would push you to a Ben Shapiro video." Though Shapiro describes himself as a conservative political commentator, his views are controversial — and some are outright discriminatory. He's suggested, for example, that transgender people suffer...