Safari blocks domains used to link email addresses to browsing activity

Apple says Safari and WebKit block network access to identity resolution infrastructure in its iOS, iPadOS, macOS and visionOS 27 releases. The protection targets third parties that collect email addresses entered on websites and return tracking identifiers linked to those addresses. Blocking those domains prevents email addresses from reaching the tracking servers, cutting off the subsequent creation and use of identifiers for cross-site tracking. Apple says changing a network request's structure cannot bypass the domain-level block. The protection targets third-party tracking infrastructure while preserving websites' ability to personalize services using their own customer information.