How Facebook Figures Out Everyone You've Ever Met (gizmodo.com)
"I deleted Facebook after it recommended as People You May Know a man who was defense counsel on one of my cases. We had only communicated through my work email, which is not connected to my Facebook, which convinced me Facebook was scanning my work email," an attorney told Gizmodo. Kashmir Hill, a reporter at the news outlet, who recently documented how Facebook figured out a connection between her and a family member she did not know existed, shares several more instances others have reported and explains how Facebook gathers information. She reports: Behind the Facebook profile you've built for yourself is another one, a shadow profile, built from the inboxes and smartphones of other Facebook users. Contact information you've never given the network gets associated with your account, making it easier for Facebook to more completely map your social connections. Because shadow-profile connections happen inside Facebook's algorithmic black box, people can't see how deep the data-mining of their lives truly is, until an uncanny recommendation pops up. Facebook isn't scanning the work email of the attorney above. But it likely has her work email address on file, even if she never gave it to Facebook herself. If anyone who has the lawyer's address in their contacts has chosen to share it with Facebook, the company can link her to anyone else who has it, such as the defense counsel in one of her cases. Facebook will not confirm how it makes specific People You May Know connections, and a Facebook spokesperson suggested that there could be other plausible explanations for most of those examples -- "mutual friendships," or people being "in the same city/network." The spokesperson did say that of the stories on the list, the lawyer was the likeliest case for a shadow-profile connection. Handing over address books is one of the first steps Facebook asks people to take when they initially sign up, so that they can "Find Friends." The problem with all this, Hill writes, is that Facebook doesn't explicitly say the scale at which it would be using the contact information it gleans from a user's address book. Furthermore, most people are not aware that Facebook is using contact information taken from their phones for these purposes.
LinkedIn Also does this.
It's just more in your face about it.
~ People that think they are better than anyone else for any reason are the cause of all the strife in the world.
I disable the FB app that the cell provider baked into the Android rom so even though it spouts dire warnings about the system not working properly if that's done. I assume that's enough to prevent it from sucking out my info but who knows for certain anymore and what about people who don't disable it?
Time for new privacy laws, I guess.
Private companies should not be permitted to collect data on people not in a business relationship with them just because someone else shares it with them.
Let my sister mention my email address on her Facebook wall - Facebook shouldn't be able to do anything with it unless I am already a Facebook user and have provided that same email address.
Legislate them into purging any such mapped relationships from their databases, legislate them to ban rebuilding those relationship maps.
Just because privacy isn't important to someone else doesn't mean I should have to surrender mine.
And have none of your friends play, or your work colleagues, or your landlord, or anyone who you have ever given your phone number to.
I don't use facebook, but i'm sure i have quite the impressive shadow profile considering my wife, my son, my dad, and pretty much every other person i've ever met does use it. The article talks about how facebook uses your phone number as a unique identifier, and other peoples non-consensual contact sharing of your information, to build a shadow profile of you.
So no, its not as simple as not playing the game. You have been entered into the game if you have your phone number in anyones phone book, and come on, that's everyone. Who doesn't have a phone, either at work or at home. Unless you solely communicate with disposable burner phones, (and no one adds those numbers and your name into their phone book :P), then you are just as vulnerable. They probably even have your picture that someone helpfully tagged.
Its pretty depressing that they can get away with this, and that people don't really care and willingly help them.
As a potential lottery winner, I totally support tax cuts for the wealthy
The info that you (and other Facebook users) provide voluntarily is certainly the primary source, but I think it's reasonable to speculate that it is by no means the sole source of Facebook's "connections" capabilities. Just like anyone else who wants to know something about someone, Facebook almost certainly Google's you. In this particular situation, it's worth mentioning that court cases are typically public record, and many of those records have been made available online. Therefore, a comprehensive search of the web would likely eventually turn up a record which includes the names of the two counsels on each side of any given case, as well as other people who were involved in that case. Cross-reference those names against the Facebook user list, and there you have it: several new potential connections.
I'm expect that using the system tools to block access to the address book is probably sufficient on Android and iOS - so long as it's done before the app is ever launched.
What surprises me more is that people don't consider geolocation. Many many facebook users share their location with Facebook. It's then trivial for facebook to see that you are repeatedly in the same location at the same time as another person.
That lawyer might have met defense counsel at a couple of mediation hearings in a lawyer's office, then they went to the same court house at the same time every day for a week. It's easy to suppose they know each other.
Similarly for the sex worker who meets the same client at a handful of different hotels. Both their phones arrived at the hotel at the same time on the same days. Then they left together. Again, the connection is trivial.
At least with Google, you are paid for this data with better traffic reports and better directions. You can decide if that is worth it or not. With Facebook it seems you get nothing in return while they amass a huge amount of information you thought was private.
Here are some of the cited links:
http://mashable.com/2013/06/26/facebook-shadow-profiles/
http://www.zdnet.com/article/anger-mounts-after-facebooks-shadow-profiles-leak-in-bug/
http://www.zdnet.com/article/firm-facebooks-shadow-profiles-are-frightening-dossiers-on-everyone/
https://splinternews.com/facebook-recommended-that-this-psychiatrists-patients-f-1793861472