[1] Users can opt-out of IDFA via the "Limit Ad Tracking" (LAT) setting (and an estimated 20% do).
[2] Starting in iOS 14.5, iPadOS 14.5, and tvOS 14.5, users are prompted to decide whether to opt-in or out of IDFA sharing before apps can query it.
Since January 2021, users and developers could test this change by installing iOS 14 beta release.
[6] In July 2020, Facebook stated that this transparency requirement would likely hurt their advertising targeting.
[11] On December 15, 2020, Facebook launched a "Speak Up for Small Businesses" campaign against Apple.
[19][20] In May, 2021, Verizon-owned advertisement analytics company Flurry reported that 96% of US users opted out of IDFA sharing.