Joe Lim estimates that 90 percent of what you see on the internet is advertising in disguise, and he should know. For three years, Lim ran a company called Floodify, which at its peak operated 65,000 dummy social-media accounts used to drum up attention on behalf of paying clients. The point of this kind of marketing is that nobody is supposed to notice it. But lately, the machinery has started to show. In April, Justin Bieber headlined two consecutive weekends at Coachella. Coachella is the biggest stage in pop music save only for the Super Bowl, the kind of event that in theory generates its own attention. And yet on both weekends, a Discord server writer Lane Brown had been monitoring hosted paid campaigns for Bieber’s Coachella performances, offering clippers — people who are hired to turn a song, trailer, interview, stump speech, or whatever into short, social-media-friendly fragments — as much as a dollar per thousand views. “On social media, popular opinion is being formed, measured, and manipulated all at once, and every signal the platforms produce — a trending song, a backlash, a talking point, the feeling that ‘everybody’ is suddenly talking about the same thing — can now be fabricated by unseen actors with hidden agendas,” writes Brown. “Everybody is doing this now,” Lim says. “And if you’re not, you’re behind.” Brown reports on how the same techniques are now being used to fool people on every app they go to in order to find out what other people think, not just in music but across entertainment, politics, consumer products, and celebrity gossip: