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: 1) by fennec on Friday September 28 2018, @06:31AM (1 child)
I think you're doing the opposite of what you think. By hiding the ad, and clicking "not interested" you're just giving them more data, the is no bad data for Facebook. Hiding the ad proves you've looked at it, and clicking only the ones related to your real life may by analysed as "you already bought the stuff" so ad targeting was actually relevant but too late.
(Score: 0) by Anonymous Coward on Friday September 28 2018, @03:08PM
They already have an option for "already own/purchased" - I never select that. Sometimes I mark the ads as offensive just to throw them a curve.