"The 13-year-old Utah boy hung out in the typical online spaces for someone his age: The chat app Discord. The gaming platform Roblox. And, of course, Twitter. But for more than two months last year, on those very platforms, the boy was being sexually groomed by an adult who was 13 years older and hundreds of miles away. It started in private messages then moved into public view on Twitter. It ended in a horror story. The boy’s father went to check on him one night and found him missing, his window open, the bedroom freezing. The boy was allegedly...