Apple introduced two-factor authentication (as an option) on iTunes, the App Store or iBookstore. Apple also announced that May 1 would be the end date for app developers using the Unique Device Identifier (UDID) Apple announced in March 2012 that it would no longer allow developers to use the UDID. The move followed a security breach at BlueToad, a Florida-based technology provider for digital publishers, which exposed more than 1 million Apple UDIDs. The FTC has brought privacy charges against Facebook and Google.”]
Source: https://www.csoonline.com/article/2133127/facing-ftc-pressure–apple-bolsters-privacy–security.html