Overview
- Apple disclosed in a WebKit blog post on Monday that Safari now targets “identity resolution,” the practice of converting emails, phone numbers, and device signals into stable IDs used to track people across websites.
- The protection is enforced at the domain level across iPhone, iPad, Mac and Vision Pro and Apple can add or change entries on a dynamic blocklist without issuing an OS update.
- Early in a September rollout Safari cut network access to domains tied to LiveRamp, ID5, Permutive, Audigent and The Trade Desk, with The Trade Desk’s ad‑serving domain briefly blocked and later restored.
- Publishers and adtech companies warn the rules will reduce advertisers’ reach on the open web, make campaign measurement and frequency control harder, raise costs to find audiences, and could shift budgets toward Google and Meta.
- Ad firms are testing server‑side and other mitigations while industry groups press for more transparency and some executives question competitive risks because Apple runs the browser engine and is growing its own ad business.