Let's go with this for a start: https://appleinsider.com/articles/20/07/30/facebook-says-apples-ios-14-could-hinder-ad-revenue https://appleinsider.com/articles

Let's go with this for a start: https://appleinsider.com/articles/20/07/30/facebook-says-apples-ios-14-could-hinder-ad-revenue https://appleinsider.com/articles/20/07/30/facebook-says-app... Also, notice that FB has done everything possible to gather information. Frankly, the NSA should just hire FB to do their work - it'b be faster and cheaper. Locking stuff down is hard. Doing it with multiple app stores will be impossible.