https://gizmodo.com/facebook-is-giving-advertisers-access-to-your-shadow-co-1828476051:
Facebook is not content to use the contact information you willingly put into your Facebook profile for advertising. It is also using contact information you handed over for security purposes and contact information you didn't hand over at all, but that was collected from other people's contact books, a hidden layer of details Facebook has about you that I've come to call "shadow contact information." I managed to place an ad in front of Alan Mislove by targeting his shadow profile. This means that the junk email address that you hand over for discounts or for shady online shopping is likely associated with your account and being used to target you with ads.
(Score: 2) by PiMuNu on Friday September 28 2018, @08:53AM
GDPR makes large fines possible. Facebook can, literally, be fined into the turf. This is even in EU's interest because they don't pay taxes and provide very little of value. They can't fine, e.g. banks or utilities into the ground because the modern world would not function without them.