Apple's 'Ask App Not to Track' Still Crucial for iPhone Privacy in 2025

• Apple's App Tracking Transparency (ATT), introduced in iOS 14.5, fundamentally changed how third-party apps collect user data, giving iPhone users a system-level choice.
• "Ask App Not to Track" blocks access to the Identifier for Advertisers (IDFA), preventing apps from easily linking user behavior across different applications and websites.
• Apple uses "Ask" instead of "Deny" because while it blocks IDFA, it cannot control all tracking methods, such as user-provided email or phone numbers within an app.
• ATT remains effective in 2025, significantly reducing cross-app tracking and impacting advertiser revenue, as acknowledged by platforms like Meta.
• Advertisers have adapted with methods like device fingerprinting and contextual advertising, which are less precise and more costly than IDFA-based tracking, affirming ATT's impact.

Why It Matters: Apple's 'Ask App Not to Track' still empowers iPhone users by limiting invasive cross-app tracking.