Facebook Is Giving Advertisers Access To Your Shadow Contact Information (gizmodo.com) 130
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.
Re:Simple fix (Score:4, Funny)
It's interesting to me that you believe they don't already have it. I genuinely believe that they're asking for your number so they can help protect your account... which said data is kept separate and compartmentalized from the data they know about you for advertising purposes.
Re:Simple fix (Score:5, Insightful)
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.
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Younger people don't realize that there used to be these books published, and given to everyone for free known as "phone books", and they li
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How did we even survive the 20th century?
We opted out of the public phone book. In fact the phone company used to ask you if you wanted to opt out when you signed up for service.
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I remember the phone company used to charge for the privilege of having an unlisted number.
Re:Simple fix (Score:4, Informative)
I think we're missing the key point of TFA - Facebook knows stuff that it claims not to know.
Here's the scenario they played out:
Alice and Bob have an offline transaction, and as some part of it, Alice gives Bob her landline phone number.
Alice has a Facebook profile, but never links her landline phone number to it.
Bob buys a Facebook ad, targeted to Alice's landline.
Alice sees the ad.
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I think we're missing the key point of TFA - Facebook knows stuff that it claims not to know.
They didn't claim not to know contact information of Facebook users. From the /. article linked to as evidence that "Facebook denied doing this":
So, these "shadow profiles" are for people who have never signed up for Facebook. Alan Mislove IS A FACEBOOK USER, and is signed up to that service. The profile that Faceboo
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There were two different scenarios called out in the article, and the summary:
1. Information which Facebook has on people who are Facebook users, which they have not provided to Facebook and is not shown on their profile (but which Facebook may have gathered as part of a shadow profile for the user) but is targetable by advertisements
2. Information which users have provided to Facebook for purposes other than updating their profile, which is not shown on their profile, but is still targetable by advertiseme
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1. Information which Facebook has on people who are Facebook users, which they have not provided to Facebook and is not shown on their profile (but which Facebook may have gathered as part of a shadow profile for the user) but is targetable by advertisements
Facebook users DO NOT HAVE SHADOW PROFILES. By definition. Mislove is a FACEBOOK USER, and Facebook could have linked his super secret office phone number to his account via any number of means that he wasn't aware of, but that data is not a shadow profile.
2. Information which users have provided to Facebook for purposes other than updating their profile, which is not shown on their profile, but is still targetable by advertisements
And to that I say "do'h". They provided data to Facebook and expect Facebook not to have the data. It's not shown in their profile because it wasn't made visible to the public. But advertisers being able to target using that data is NOT revealing anything
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Yes, it is a problem that your friends are giving your super-secret personal information to Facebook or other data aggregators. It's a problem with your friends.
To be fair, when the Facebook app asks for permission to access your contacts in order to look for your friends, it doesn't say "and also to fill out their shadow profiles and target ads at them". I don't know if there is anything in the ToS that they didn't read but either way it's not what most people expect to happen.
Go ahead, call them naive. It's still Facebook being deceptive.
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To be fair, when the Facebook app asks for permission to access your contacts in order to look for your friends, it doesn't say "and also to fill out their shadow profiles and target ads at them".
Can you explain in simple terms how Facebook targets non-users for ads?
And why it is Facebook targeting them for ads when it is advertisers buying the advertising and providing the contact information being used to target them?
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Wow... so many people misread my comment. They keep it compartmentalized from YOU. They know your phone number, so the most convenient user interface design would be to simply ask "do you want to secure your account with your phone number " and not even bother asking you to type it in. They let you type it in to maintain the appearance that they don't really know all that much about you.
Re:Simple fix (Score:4, Interesting)
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I genuinely believe that they're asking for your number so they can help protect your account...
Did you read TFA? It's somewhat related to your belief.
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I did... perhaps my comment was too subtle. I meant to imply that they already know full what your phone number is... they're asking so they can maintain the illusion of privacy while they add protection (for what it's worth) to your account. Or stated another way, they maintain the illusion of privacy while adding the illusion of security. Thus, the only reason to ask you that question, is in fact to add two factor security, and could just as easily been done by asking "do you want to protect your accou
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I genuinely believe that they're asking for your number so they can help protect your account... which said data is kept separate and compartmentalized from the data they know about you for advertising purposes.
You may be the stupidest person on slashdot.
The entire point of Facebook existing is to collect data. Why would they keep anything compartmentalized?
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Wow... are you leading with an insult to distract from your ignorance, or is this how you start every conversation? They keep it compartmentalized, because some of what they are doing is illegal! And it undermines their business model if the law is changed to make more of what they do illegal. If they simply started using your phone number (which they already have) to secure your account, then people would realize how much Facebook knows about them, and then pressure would increase on politicians to prot
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Doesn't that just give your personal information to Google instead?
Re:Simple fix (Score:4, Informative)
Actually, no, "Google Authenticator" is just an app which implements the OATH TOTP protocol (a.k.a. RFC 6238) [ietf.org]. There are several other implementations out there, and they're pretty much all compatible.
It's possible (although I don't know if Google's app does so) for the generator application to be a purely offline app with no external access whatsoever.
It functions essentially like one of the old RSA SecurID [google.com.au] tokens - an offline token generating 6 or 8 digit time-based id numbers.
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Re:Simple fix (Score:5, Interesting)
I guess you didn't read the fucking summary: "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."
So Facebook already had the phone number, even though Mislove didn't provide it..... probably extracted from the white pages (phonebook).
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Landline numbers have been available in criss-cross directories since WWII. That information is public. I mean, it's the guy's office for chrissake. He's in the damn Yellow Pages.
Re:Simple fix (Score:5, Informative)
SInce when are businesses/universities desk lines in either the white OR yellow pages?
They're not, and have never been.
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Even better. They're on the fucking campus directory which is on the fucking website.
And if you were to give me a name and a company, I could come up with a desk extension in about five minutes, without subterfuge or resorting to Facebook.
Please. The guy probably gives out business cards with his office phone number to random girls (or boys) at the bar. If you have a business and your phone number is a super double top
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Even better. They're on the fucking campus directory which is on the fucking website.
And if you were to give me a name and a company, I could come up with a desk extension in about five minutes, without subterfuge or resorting to Facebook.
Please. The guy probably gives out business cards with his office phone number to random girls (or boys) at the bar. If you have a business and your phone number is a super double top secret, you're probably not going to stay in business long.
Yeah, and they get from the fucking campus directory or the business cards into Facebook...how? Facebook doesn't fucking send out fucking bots to scrape fucking campus directories, nor is there a fucking VP of Typing In Fucking Business Cards, although that might be a good job for you with your fucking critical thinking skillz.
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Public information is public. Who cares how Facebook got this guy's phone number if it was already public?
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Yeah, and they get from the fucking campus directory or the business cards into Facebook...how?
I cannot access "Alan Mislove" on Facebook. All I find are links to this story. HOWEVER -- Google is your friend. If you google his name, the FIRST link provided is to his college webpage, which provides his name, address, telephone number, and a link to his "personal" website, which includes similar information PLUS a link to a map showing where he works. The college page is even helpful enough to list the office phone number with a "tel:" link so it is trivial to identify it as such.
The second and third
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I assume Alan has friends. I think it's also safe to assume that Alan has friends who know his office phone number. I'm going to make a risky assumption here, but I'm going to assume some of those friends use facebook. Now some of those friends also probably use messenger and have upload their contact list....
Googling not required for facebook.
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For what possible reason are you convinced that Facebook doesn't send out bot to scrape data from not just campus directories, but everywhere on the net?
I surely expect they do. As well as any IOT devices, public records posted online, and Google's database besides.
This is their business. They collect data on individuals and sell it.
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Nope, but they are often available on public web pages
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My university published a "white pages" listing every professor's desk phone. It was also published online, so Google/others could easily gain access to it.
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Google crawls the internet. Facebook doesn't. (and, of course, just because it's online doesn't mean that its in a search engine. [wikipedia.org]
Probably not (Score:1)
It was scraped from Kashmir Hill's phone. HE had the number in his contacts. It was probably typed in as Alan Mislove. By default, contacts autosync to Facebook. Since Hill's FB app was on his phone and so was that contact, FB could assume it's a legit name and number. So Hill posts the same name and number into FB ads and the app just goes, "oh you want to talk to that dude on your phone". I don't know if any of that is legal or not but FB knows who is in your contacts list, even if you don't allow i
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I'd wager the answer is even easier simpler than that - someone else has Alan's office number in their contacts list and it was uploaded to Facebook.
FWIW this isn't anything to do with a shadow account (which is an account created by Facebook for someone who has never joined Facebook) since Alan was already on Facebook. It's more about Facebook storing additional informati
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Unless you gave it to them back when they only let students sign up, you didn't give it to them. At most you confirmed it.
What actually happened was they got it from somebody who had your phone number in their contact list, either on their computer (email), or on their phone.
When people create a facebook account, facebook already had their phone number. When they ask you for it, they're just trying to confirm that it is still current.
Your naivete would be cute, except that you purport to be a nerd. Naive ne
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Or, as in this specific case, sine it's an office number of a landline, it's available in any of dozens of public databases. Like the phone book.
I'm all for privacy, but are people too young to remember phone books? Let's not get hysterical. "Facebook figured out that I'm in California from a photo of me and my car with California license plates in fron
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Your point seems to only be, "I didn't want privacy, why did anybody else want any?"
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No, my point is "I do want privacy, but hysteria over a publicly-available phone number being publicly-available doesn't help us get there."
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You sound like my wife. Honey, is that you?
At least read the summary before commenting (Score:2)
...a number Mislove has never provided to Facebook...
The article explains how Facebook got the phone number indirectly because another company had the phone number.
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I'm all for that, but he's going to have to get in line behind at least one current nominee for the Supreme Court and over a dozen members of the Trump administration.
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It's almost like that 2 factor authorization tied to your phone... wasn't for security.
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Which clearly indicates you didn't RTFA, so let me help you out here.
If one of your idiot friends signs up for Facebook, is stupid enough to say "oh, sure, here's my contact list you can slurp up" ... (or even worse gives them the fucking password to their email like a complete fucking moron) ... then that information about you is provided by a third party, and you have no control over it:
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No shit. Do you know which website you're on?
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This is the same as Echelon. "USA: We don't spy on our citizens. Hey UK, here is all of the data on our citizens, please spy on them. UK: We don't spy on our citizens. Hey USA, here is all of the data on our citizens, please spy on them."
I don't care who provided my personal details, they are still mine. The fact that facebook is knowingly trying to make an end-run around privacy laws means they are complicit. Zuck and friends should be sitting in jail.
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Don't give Facebook your phone number. It's not required. Every few months they ask, "Do you want to give us your phone number to help us secure your account?" and I answer, "Fuck off, Facebook", as I click the "No" button and move on.
You don't even have the option to opt-in or out of them having your phone number. Someone with your phone number syncs contact info with Facebook and they populate your data. Where do you think Facebook gets this data? Did you even read the summary?
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Except that still doesn't work. I'm pretty sure I've got a fairly comprehensive shadow account. For example, I've never given Facebook my phone numbers or email / real addresses, but I'm pretty sure they have my name attached to them thanks to at least one recruiter who uses Facebook and had those details in their contact lists. One might have a landline, another a mobile, a third an address, etc., but all had my name.
Point being, it isn't necessarily your friends who have inadvertently released the data, i
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Re:Simple fix (Score:5, Insightful)
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.
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Just stop using facebook. I know it seems like going vegan as a meat eater, but honestly after about 2 weeks you will love it. Social media software such as facebook and twitter serve no useful function. They bring noise, angry, hate, and fear and little else. They are helping us destroy our society. I guess if you want to see the fall of man, keep using social media.
FFS people haven't you had enough of Zuckerbook? (Score:1)
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I haven't had a Facebook account for years... this morning after reading the story about the Founder of WhatsApp, and a few days ago reading the articles from the founders of Instagram, I decided to delete my Instagram and WhatsApp accounts as well. The thing that disturbed me was that Instagram kept prompting me to follow users, claiming they were in my contacts list... but I had NEVER given Instagram permission to my contact list... so how did they know? Too creepy for me. I'm out. Instagram was a gia
Re:FFS people haven't you had enough of Zuckerbook (Score:5, Funny)
Friends don't let friends facebook.
Simple answer ... (Score:1)
The answer to this is Mark Zuckerberg is a greedy, lying sack of shit, who has now apparently lied to Congressional comittees.
This is precisely why my ad blockers block everything related to Facebook, and any other ad/analytics company I can.
I don't trust their "privacy policies", so I have my own .. which boils down to "most th
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Sure, but then he'll play the clueless card "Oh, I didn't know" or "I meant 'didn't' not 'did'" or somesuch.
Besides, I always thought the shadow profiles were what they built to track those people who are not part of Facebook.
FB didn't give the guy the # (Score:2)
Umm... FB didn't give the "advertiser" the number or access to it. The advertiser said "target this phone number". Wonder what would happen if you were to do similar for all of the area code combos (other than toll/toll free numbers) and 867-5309 ?
Heck, almost wish I didn't have to worry about money just so I could do it, and run an ad asking for Jenny...
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I don't have any Earl Grey Tea in my house right now, but if you show up on my door step and offer me $50 to make you a cup of it, I *do* know where I can go look to find it.
Lots of places have info on you (and me, and everyone else) that you've never given them, but you have given others.
How many times have you gotten spam email or one of the outlook virus emails from someone because some 3rd party had your address in their contact list? That is basically what happened here...
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Except it is happening on a mass basis with Facebook constructing profiles on all people, as privacy invasive as possible (now probably to skirt investigation, they are contract it out to an off balance sheet company owned by Facebook executives, so Facebook isn't doing oh no, company Facebook owns is doing it, naughty, naughty people that they are, here is a list https://en.wikipedia.org/wiki/... [wikipedia.org], take your pick of participants in the lie, Facebook ain't doing absolutely not, some company on this list is t
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But, if you testify to congress that you don't have any Earl Grey, and you suddenly show up with a cup of Tea, Earl Grey, Hot; you can bet your ass is going to be hauled in front of congress again.
What a twisted sense of "privacy" (Score:5, Insightful)
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.
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This is clearly illegal in the EU. I hope they get the maximum fine, currently 4% of global turnover if I'm not mistaken.
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I hope they get the maximum fine, currently 4% of global turnover if I'm not mistaken.
Yes, and the world has been waiting for a good test case to see how that theoretical penalty plays out in the real world. This would be a doozy.
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Looks like their 2017 turnover was $40bn. So $1.6bn maximum fine.
Re: Zuckerberg denied knowledge of it? (Score:1)
Or he's a lying sack of shit.
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I am pretty sure "I'm a big dummy that has no idea what goes on in my company worth billions of dollars" is not a valid defense in court.
That isnt a shadow profile (Score:1)
Re:That isnt a shadow profile (Score:5, Insightful)
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.
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That isn't a shadow profile. ... the user never provided to Facebook but was presumably attached by other sources.
So, you're saying it is not a True Shadow Account, because it is only a Shadow Data Related To An Account.
That seems to submarine your blathering, without even getting to the part where you say, "Golly, somebody else might be doing it too, so it can't be wrong. Bad things can only happen once."
If you believe for a second... (Score:1)
That giant social media doesn't already know exactly who you are, who you associate with and what your habits are... I have a lovely bridge for sale.
Even if you don't have an account, your friends do, your spouse does, your organization/company does. They may not necessarily know your name definitively, but you can be damn sure they have, thru data scraping and aggregation (including combing thru other users uploaded contact lists, their posts, their pictures, their location history, etc...), have compile
Or.. They just Googled it (Score:2)
Granted I don't know the number called, but the Facebook system may have just asked Google and parsed the results, nothing shadow about it..
I mean I asked Google and one of the many pages I received was https://www.ccis.northeastern.edu/people/alan-mislove/ which contains a phone number...
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Sorry, meant number they used not called
Key problem with 2-factor authentication (Score:3)
This is my strongest (but not only) objection to 2 factor authentication as it is frequently used. The 2nd factor is usually a phone, and nothing seems to keep the company from selling that very valuable information.
The claims about security are largely bogus as the many social hacks around 2 factor authentication have shown.
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Text message is just the worst form of 2 factor auth. Using time based codes with an app or a security token is pretty secure.
Illegal is new normal (Score:2)
All the big internet companies operate illegally. Facebook keeps lying to us, Slashdot keeps harassing me for "consent" to monetise my data, everybody is in on it, everybody does it. I nearly prefer the sites that just do not give you access if they cannot set cookies, or you have an ad blocker. At least that is honest (or I am too optimistic there, too?).
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Sadly the masses don't care.
The data breaches and selling of their data isn't enough.
I don't know what will be the catalyst where they finally go "I'm mad as hell and I'm not going to take it anymore."
Ideas anyone?