Slashdot Mirror
Facebook Is Giving Advertisers Access To Your Shadow Contact Information (gizmodo.com)
Kashmir Hill, reporting for Gizmodo: Last week, I ran an ad on Facebook targeted at a computer science professor named Alan Mislove. Mislove studies how privacy works on social networks and had a theory that Facebook is letting advertisers reach users with contact information collected in surprising ways. I was helping him test the theory by targeting him in a way Facebook had previously told me wouldn't work. I directed the ad to display to a Facebook account connected to the landline number for Alan Mislove's office, a number Mislove has never provided to Facebook. He saw the ad within hours.
One of the many ways that ads get in front of your eyeballs on Facebook and Instagram is that the social networking giant lets an advertiser upload a list of phone numbers or email addresses it has on file; it will then put an ad in front of accounts associated with that contact information. A clothing retailer can put an ad for a dress in the Instagram feeds of women who have purchased from them before, a politician can place Facebook ads in front of anyone on his mailing list, or a casino can offer deals to the email addresses of people suspected of having a gambling addiction. Facebook calls this a "custom audience." You might assume that you could go to your Facebook profile and look at your "contact and basic info" page to see what email addresses and phone numbers are associated with your account, and thus what advertisers can use to target you. But as is so often the case with this highly efficient data-miner posing as a way to keep in contact with your friends, it's going about it in a less transparent and more invasive way.
[...] Giridhari Venkatadri, Piotr Sapiezynski, and Alan Mislove of Northeastern University, along with Elena Lucherini of Princeton University, did a series of tests that involved handing contact information over to Facebook for a group of test accounts in different ways and then seeing whether that information could be used by an advertiser. They came up with a novel way to detect whether that information became available to advertisers by looking at the stats provided by Facebook about the size of an audience after contact information is uploaded. They go into this in greater length and technical detail in their paper [PDF]. They found that when a user gives Facebook a phone number for two-factor authentication or in order to receive alerts about new log-ins to a user's account, that phone number became targetable by an advertiser within a couple of weeks. Officially, Facebook denies the existence of shadow profiles. In a hearing with the House Energy & Commerce Committee earlier this year, when New Mexico Representative Ben Lujan asked Facebook CEO Mark Zuckerberg if he was aware of the so-called practice of building "shadow profiles", Zuckerberg denied knowledge of it.
One of the many ways that ads get in front of your eyeballs on Facebook and Instagram is that the social networking giant lets an advertiser upload a list of phone numbers or email addresses it has on file; it will then put an ad in front of accounts associated with that contact information. A clothing retailer can put an ad for a dress in the Instagram feeds of women who have purchased from them before, a politician can place Facebook ads in front of anyone on his mailing list, or a casino can offer deals to the email addresses of people suspected of having a gambling addiction. Facebook calls this a "custom audience." You might assume that you could go to your Facebook profile and look at your "contact and basic info" page to see what email addresses and phone numbers are associated with your account, and thus what advertisers can use to target you. But as is so often the case with this highly efficient data-miner posing as a way to keep in contact with your friends, it's going about it in a less transparent and more invasive way.
[...] Giridhari Venkatadri, Piotr Sapiezynski, and Alan Mislove of Northeastern University, along with Elena Lucherini of Princeton University, did a series of tests that involved handing contact information over to Facebook for a group of test accounts in different ways and then seeing whether that information could be used by an advertiser. They came up with a novel way to detect whether that information became available to advertisers by looking at the stats provided by Facebook about the size of an audience after contact information is uploaded. They go into this in greater length and technical detail in their paper [PDF]. They found that when a user gives Facebook a phone number for two-factor authentication or in order to receive alerts about new log-ins to a user's account, that phone number became targetable by an advertiser within a couple of weeks. Officially, Facebook denies the existence of shadow profiles. In a hearing with the House Energy & Commerce Committee earlier this year, when New Mexico Representative Ben Lujan asked Facebook CEO Mark Zuckerberg if he was aware of the so-called practice of building "shadow profiles", Zuckerberg denied knowledge of it.
which said data is kept separate and compartmentalized from the data they know about you for advertising purposes.
Why would you ever think that any data that they have about you is "compartmentalized" away from the advertising side of the operation? Are you really that naive?
As for TFA claiming that giving Facebook a number you think is private is helping other people you don't want to find you, to find you -- the person who targeted the ad had to GIVE THEM THE NUMBER for it to target the recipient. In other words, Facebook did not help anyone find this elusive professor, the person trying to "find him" already had his private phone number.
Had it been Facebook saying, "I recognize that name, would you like his private phone number?" that would be something different.
FTFA:
The researchers also found that if User A, whom we’ll call Anna, shares her contacts with Facebook, including a previously unknown phone number for User B, whom we’ll call Ben, advertisers will be able to target Ben with an ad using that phone number, which I call “shadow contact information,” about a month later. Ben can’t access his shadow contact information, because that would violate Anna’s privacy, according to Facebook, so he can’t see it or delete it, and he can’t keep advertisers from using it either.
The lead author on the paper, Giridhari Venkatadri, said this was the most surprising finding, that Facebook was targeted ads using information “that was not directly provided by the user, or even revealed to the user.”
So informing me that someone else has revealed a piece of my personal information to Facebook (and particularly one that I've not revealed to Facebook myself) is somehow a violation of the other person's privacy?
Give me a break.
That isn't a shadow profile. What they are describing is an existing Facebook account which has a phone number tied to it that the user never provided to Facebook but was presumably attached by other sources.
I see what you mean, but that's probably precisely the kind of word game that allowed Zuckerberg to deny the practice. It's not technically a shadow profile in terms of a profile belonging to a person who has never signed up. However, it is shadow data attached to a voluntary profile, or in other words, hidden data scraped from online shadow profiles but associated with a non-shadow profile so that the claim can be made that it is not, in fact, a shadow profile. But this is mere semantics. Not only can this be understood as a shadow profile hiding underneath a voluntary profile, but it's even possible that the shadow data is actually stored separately and only probatively associated with the voluntary profile, in which case only this loose and volatile association would ground the pretense that it is not a shadow profile.
Incipiamus, fratres, servire Domino Deo, quia hucusque vix vel parum in nullo profecimus.
Actually it won't, unless you live a hermit's life in a cabin in the woods.
Do you ever buy on line? Facebook knows about it. As does Amazon and Google.
Remember the equifax data breach? Does anybody with a brain actually believe that Google, Facebook, the NSA et all hasn't scraped all of that data? Purely for their own protection of course.
Do you have friends? Family? You can bet Facebook has gotten data from them on you. Plenty of recent data.
Burning Facebook's servers to the ground being impossible you're right about that.
As someone who knows history I know that when human populations were smaller and people mostly lived in villages privacy was non-existent. Faster transportation and bigger urban populations gave humans the illusion of privacy for a couple of centuries, but we're pretty much back to the everyone knows your business village now, except it's a global village.