Apple published a WebKit blog post explaining why Safari and other iPhone and iPad browsers now block domains run by companies that link a person’s email, phone number, IP address and device details to track them across sites, a practice Apple calls “identity resolution.” The blocks began earlier this month without warning and hit The Trade Desk, LiveRamp, ID5, Permutive and Audigent, briefly stopping The Trade Desk from serving any ads at all until Apple fixed it. Apple said people who give a site their email to log in don’t expect it to be passed to other companies for tracking, and it is blocking entire domains so those companies can’t get around the rule. Ad buyers told Business Insider they expect less reach and higher prices on the open web as more people update to iOS 27.
