The MarkUp: “A spreadsheet on ad platform Xandr’s website revealed a massive collection of “audience segments” used to target consumers based on highly specific, sometimes intimate information and inferences.” – By Jon Keegan and Joel Eastwood. “If you spend any time online, you probably have some idea that the digital ad industry is constantly collecting data about you, including a lot of personal information, and sorting you into specialized categories so you’re more likely to buy the things they advertise to you. But in a rare look at just how deep—and weird—the rabbit hole of targeted advertising gets, The Markup has analyzed a database of 650,000 of these audience segments, newly unearthed on the website of Microsoft’s ad platform Xandr. The trove of data indicates that advertisers could also target people based on sensitive information like being “heavy purchasers” of pregnancy test kits, having an interest in brain tumors, being prone to depression, visiting places of worship, or feeling “easily deflated” or that they “get a raw deal out of life.” Many of the Xandr ad categories are more prosaic, classifying people as “Affluent Millennials,” for example, or as “Dunkin Donuts Visitors.” Industry critics have raised questions about the accuracy of this type of targeting. And the practice of slicing and dicing audiences for advertisers is an old one. But the exposure of a collection of audience segments this size offers consumers an unusual look at how they and their families are packaged, described, and categorized by ad companies. Because the segments also include the names of the companies involved in creating them, they also shed light on how disparate pools of personal data—collected by tracking people’s online activity and real-world movements—are combined into bespoke, branded groups of potential ad viewers that can be marketed to publishers and advertisers…”