“Maybe it turns out Spotify shares the information with a data broker, which is, in turn, absolutely happy to share this information with another actor to make a very detailed profile about me,” Rossetti continued. “It’s Spotify, it’s dating apps, it’s what I read online.” This practice is called “ID syncing,” in which companies compile data from various sources, from cookies and mobile identifiers, fingerprinting on browsers. Taken altogether, these companies attempt to map detailed user profiles that could be used for job selection, background checks, political micro-targeting, and more.
