Facebook shares your personal information that you have never submitted to its social network with its advertisers. Of course you can't delete them from their files.
A document (PDF), published by researchers at Northeastern University and Princeton University, examines how ad targeting works on Facebook.
Let's see what the researchers found:
Say you have a mobile phone number and a landline and just uploaded the first to your Facebook profile. If an advertiser has the mobile number in his database, he can use it to target you with ads on Facebook. If the advertiser also has your landline number, it could target you with and with ads.
Is it possible to have it, if you have not shared your Facebook number?
You may not have given it to Facebook, but if you gave your station number to a friend who is also on the social network and has saved it in his address book (which he has access to Facebook), then he can associate it with your profile.
Such as he says the Gizmodo, Facebook did not previously admit to doing so. In addition, if you give the social network a mobile phone number only to authenticate two factors, that number ends up again in the advertisers' lists even though they are not in public view on Facebook.
Naturally, all of the above is not one of Facebook's biggest privacy violations, but once again proves that the company does not care about your privacy at all.