Behind the One-Way Mirror (EFF)

The Electronic Frontier Foundation has posted a detailedstudy on third-party corporate surveillance on the Internet (andbeyond). "Both Google and Apple encourage developers to use ad IDsfor behavioral profiling in lieu of other identifiers like IMEI or phonenumber. Ostensibly, this gives users more control over how they aretracked, since users can reset their identifiers by hand if theychoose. However, in practice, even if a user goes to the trouble to resettheir ad ID, it's very easy for trackers to identify them across resets byusing other identifiers, like IP address or in-app storage. Android'sdeveloper policy instructs trackers not to engage in such behavior, but theplatform has no technical safeguards to stop it. In February 2019, a studyfound that over 18,000 apps on the Play store were violating Google'spolicy."