Apple is protecting Safari users' identities online in iOS 27 and macOS 27 by making it harder for advertising firms to determine who is accessing a webpage, and by blocking some web traffic. Privacy has long been a core tenet of Apple's design philosophy, and web browsing remains one of the more challenging activities to keep users anonymous.
Cross-site cookies have been blocked in Safari for six years, preventing advertisers from using a single cookie to track a person's browsing across multiple websites. App Tracking Transparency has also helped at the app level. However, tracking firms are still building profiles to personalize online ads, using a method called "identity resolution."
Instead of cookies, this technique collects email addresses through third-party firms, often when users log into a website or sign up for a newsletter. The address is stored, assigned an opaque tracking ID, and that ID is sent to the webpage. The ID then identifies the user on future visits, and a single profile can hold multiple IDs, allowing tracking across sites much like cross-site cookies did.
Apple considers email addresses a form of personally identifiable information, similar to a phone number. Users provide them for one purpose, signing in, not for building advertising profiles. Apple says first-party personalization is not the problem. Its technology aims to block the third-party identity graphs that link these identifiers together.
Source: AppleInsider · Summarized by HeadlinesBriefing