App Store apps leak user data to global ad-tech networks

A report shows a large swath of apps in the App Store transmit users’ data to a sprawling array of advertising and tracking vendors. Collected data include IP addresses, device identifiers, probabilistic IDs, location (precise and non-precise), browsing and interaction data, and user profiles, with many vendors using cookies for extended periods (months to years) or other storage. Consent models vary, some vendors claim legitimate interest while others state they don’t use cookies, and privacy policies differ across providers. The result is data flowing from millions of users to numerous ad-tech networks, underscoring privacy concerns about cross-app data sharing and the transparency of storage and consent practices.