Facebook merges your advertiser's phone number, even if you do not specify it in your profile

Researchers at Princeton University and Northeastern University in Boston found that Facebook gives you access to phone numbers of users to send targeted advertising. And to get even mailing lists those numbers, which are not specified in the profile.

Professor at Northeastern University Mislov Alan (Alan Mislove) and the editor of Gizmodo Hill Kashmir (Kashmir Hill) conducted a simple experiment. Hill created the ad, pointing Mislova phone number. After some time, he saw an ad in your feed Facebook. According Mislova created advertising Hill loomed a few hours before his eyes. That's just it does not specify your phone number in the Facebook profile.

On Facebook there is a special

tool for advertisers called Custom Audiences. It allows you to show ads to specific people, downloading the list of their phone numbers or email. StudyInvestigating sources of PII used in Facebook's targeted advertising Mislova and his colleagues confirmed that the list and get those numbers that users do hidden or not indicated in the profile. Facebook takes for targeting of advertising and numbers of your contacts on your phone, and even your number listed for two-factor authentication, which, in theory, should not be shown to anyone.

For the sake of testing their theory, researchers have created another advertising newsletter, pointing it at this time several hundred phone numbers belonging to students and staff of the North-East University. Most of them saw its advertising, though it did not specify their numbers in the profiles.

So how does it work?

When you install the Facebook app on your smartphone, it gets access to your contacts. So all the names, phone numbers and email addresses of your friends are at his disposal.

It is necessary that the social network to recommend you to friends. In addition, this information is used for targeting ads.

Numbers and names of people automatically associated with their Facebook profiles in social networks. So, even if you are not tied to the number of your page, social network know it someone you know, without asking permission. And if this number will be in the pool of advertisers, the latter will be able to show you ads through your Facebook profile.

And it's not the only trick that uses the social network to display ads. So, Oscar Schwartz (Oscar Schwartz) from The Outline noticedThat Facebook mobile app just listens to what you say next to the phone to find out which ads are most relevant to you.

The commentary portal Gizmodo Facebook press office admitted that she really handles numbers users without their knowledge, but it does so only with good intentions - to make advertising recommendations skilful. If you are not satisfied with such arbitrary treatment of your data, it is worth thinking about removal your page or at least force the social network to collect less information about you.

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