That anonymous internet persona with an anime cartoon avatar in your Discord chat might actually be a contractor sent to spy on you. Enter the world of “threat intelligence.” It’s the term of art for a growing set of surveillance and security firms that create fake online personas to infiltrate and scrape data from private corners of the internet. The industry provides corporate and government clients with insight into conversations on private, invite-only Discord chats, WhatsApp groups, Reddit forums, and dark web message boards to help those powerful customers keep tabs on a variety of potential threats, from political hacktivists...