Stalkers, Inc.

Modern advertising is not far from the world of “Minority Report”.

Internet ads now account for around a quarter of the $500 billion global advertising business, and the confluence of mobile devices and social networks allows advertisers to track and target people to a degree once reserved for fiction. As people spend ever more time online, thousands of firms are invisibly gathering intelligence about them, as our special report explains. By monitoring the websites people visit, these companies can infer their location, income, family size, education, age, employment and much more. One data firm has compiled a billion profiles of potential customers, each with an average of 50 attributes. Consumers are lumped into “segments” such as “men in trouble”—presumed to have relationship problems because they are shopping for chocolates and flowers—or “burdened by debt: small-town singles”. When people visit websites, advertisers bid to show them precisely targeted ads. The auctions take milliseconds and the ad is displayed when the website loads.