Facebook makes it possible just like many sites to enter your phone number as secondary verification. That would promote the security of your account, but research from Gizmodo shows that your number is also used to send you targeted advertisements. As an advertiser, you can simply enter a laundry list with telephone numbers to show a targeted advertisement and if they have your number you will also get it for you.
The trouble is that a lot of people have already given their number to Facebook. Until recently, it was the only way to protect your account against unauthorized login attempts. You can now also use a 2-step authenticator (and that is a lot safer), but few people use that and so Facebook has a lot of songs that they can use. Because of general and privacy conditions .
How does Facebook get my number?
It gets even worse: because Facebook is so good at pulling in and comparing data it may also be that your phone number is known to them while you never entered it. Facebook gives you the opportunity to share your contact list with the network. If someone else does that and it happens to have your name and phone number, Facebook makes one and one two and they link your number to your person.
More will be collected, but you will not see all the shadow information that Facebook has about you. There is therefore no way to remove it from your account or to say that you do not need to be a victim of targeted advertisements. In the EU it is very illegal, but Facebook does not clarify this shadow information. The company says they do not because it is part of ‘confidential’ algorithms that Facebook uses. Kul, of course, because although they say that they are “not in a position to share the precise details of our algorithms”, it is diametrically opposed to at least European law. In addition, it is also just a sewing area.
There are now possibilities for whether or not to share your known data with the social network, but as long as they have a file of you that remains under the surface, that is of no use. It is becoming more and more apparent that there is only one way to get rid of all that sneaky stuff: just cancel your account altogether. Did those #deletefacebook people still have a point.