Who is behind your screen(s)?

One of the most important privacy cases this decade is currently in front of the Supreme Court: Carpenter v. United States. This decision will define how law enforcement interprets the Fourth Amendment regarding an individual’s cellphone. The decision hinges on whether law enforcement can use “third-party” doctrine dating from the 70s, which states that disclosing information to a third party does away with any expectation of privacy. We’ve already seen this doctrine in action. It allows law enforcement to compel cell-service providers to give historical cell-site records, without a warrant, to track down a serial cell phone thief. If SCOTUS upholds the current doctrine, then police would have free reign to monitor individuals’ cell phone location with little to no oversight. Individuals have more than just law enforcement to worry them when thinking about phone privacy. Another large group of actors are advertising firms. One challenge marketers face is how to match individuals across multiple devices to tailor user-specific marketing strategies. And this problem has potentially lucrative rewards for whoever can solve it. One study found that companies saw a $.04 revenue increase for each additional ad that a consumer was exposed to, which reinforces the importance of making multiple impressions on a consumer across multiple media platforms. Privacy concerns, among others, have caused Apple and Google to change their practices to make it much more difficult for advertising agencies to pinpoint each individual’s (their customers’) online usage over the past five or so years.  Both the IDFA (Apple) and AAID (Android) systems allow the user to opt out of its advertisement tracking system, which use these data points...