'It's a slippery slope': How young men fall into online radicalization

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."

Shapiro describes himself as a conservative political commentator, though his views are seen as controversial — and outright discriminatory by some. He's suggested, for example, that transgender people suffer from a "mental disorder."

He has a combined 9.4 million subscribers and followers on YouTube and Twitter, many of whom are young people, like Brown was when