
How Facebook knows who you might be dating online - iamben
http://www.bbc.co.uk/newsbeat/article/34518576/how-facebook-knows-who-you-might-be-dating-online
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wongarsu
The thing that I find most interesting about this article is the displayed
approach towards privacy management. People quoted in this article reveal
little about themselves in a dating network, and don't want to give enough
information to make it possible to guess their real identity. Facebook
destroys this concept by suggesting dating matches as potential facebook
friends, making it possible for their dating matches to discover all about
them in their public profiles and timeline.

That's a straightforward conflict, but it makes me wonder why people are
comfortable with revealing "all [their] information" publicly on facebook,
when their dating network behaviour shows they don't want total strangers to
know all this? Facebook provides lots of privacy controlls, allowing you to
finely tune who sees what. If you don't want strangers to know your last name,
or which area you're from, why make it publicly viewable on facebook?

Is the problem with facebook making it not simple enough to hide things from
total strangers (i.e. people you have not friended)? Is it a problem with
people never bothering to change default settings? Or is it something about
the way people use facebook that makes this apparent inconsistency actually
completely rational?

~~~
pjc50
Most people don't understand the privacy settings, and in any case they keep
changing.

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grovulent
I think this is far less mysterious than people suppose.

Hypothesis - if someone on facebook views your profile then facebook is more
likely to suggest them as a friend. Increase the probability if the person is
a low degree of separation from you.

Obviously people on dating apps are often going to be searching each other out
on facebook to see more info.

I guessed this was how facebook did it because I saw an ex of mine once on the
street (I don't have the fb app on my phone or anything like that - so I doubt
it was using location data). We never spoke - but made eye contact. Later that
day she appeared as a friend suggestion for the first time. My guess is that
she viewed my profile out of curiosity.

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emilsedgh
Something similar happened to me on Facebook.

There was someone I was meeting in real life but we had absolutely no FB
connections. No mutual friends. And I didn't even know she was on Facebook.

Suddenly I saw her on my 'Suggested friends' list.

The only reasonable explanation is that she found me on Facebook and viewed my
profile. Facebook saved the incident and suggested her to me as a friend.

Facebook forgets nothing. Nothing.

~~~
toomuchtodo
> Facebook forgets nothing. Nothing.

Export your Facebook data and check out they keep your message history with
everyone _forever_.

[https://www.facebook.com/help/131112897028467/](https://www.facebook.com/help/131112897028467/)

~~~
meric
_You will not find information or content that you have deleted because this
is deleted from Facebook servers._

[https://www.facebook.com/help/405183566203254](https://www.facebook.com/help/405183566203254)

So if you delete it, it won't be in the download.

~~~
toomuchtodo
Can you delete entire Facebook Message conversations?

~~~
meric
I think I saw that option before. I know I definitely can delete messages and
they don't appear in the download.

~~~
psykovsky
Doesn't mean they really deleted them from their servers...

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flashman
Here's my theory on how Facebook can be telling the truth here:

Your Tinder/Grindr matches are people in your local area. Your Facebook social
graph contains people in your local area, even ones you don't know, through
your local friends. The chances of one or several Tinder matches eventually
intersecting with your Facebook graph are significant. When this happens,
people interpret it as a deliberate act, not just a coincidence.

If you use Tinder in an area which does not contain any of your friends, and
people from that area subsequently show up, and have no connection to any of
your friends, that would be a lot more suspicious.

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breatheoften
This article doesn't make anything clear - though it attempts to make the
suggestion that the different social networks are communicating information
about your activities across networks. In reality it seems as tho many of
these social networks are actually just using very similar inputs to their
people suggestion algorithms (on Facebook to suggest people you might want to
be friends with, on dating networks to suggest people you might want to date).
Since many of these suggestions are made to you based on your phone number or
device location, you are likely to see the same people suggested to you by
these different networks even tho they are not sharing data about your
activities.

~~~
bhrgunatha
> Facebook goes through your phone book and checks them against other users'
> phone numbers - you give it permission to do this when you install the app.

> "What Facebook does and what Tinder does is go through your phone book,
> upload your phone book and does cross-correlation between your numbers and
> anyone else's number - and suggest people based on that," he explained.

That seems pretty clear. They grab your WHOLE address book, so there is an
established link stored in their database(s) between you and every other
person stored on your phone. From there, it's just a matter of graph
traversal.

This is one of the reasons I decided I would stick with a dumb phone and why
the mobile web (or using the web from phone or tablet) is so ripe for abuse.

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Systemic33
Most likely this is because someone on the dating profile saw the persons
profile, thought it was interesting enough to 'dox' the person.

If people knew how little information is needed to get started they would be
either terrified or amazed.

First name + Location + Instagram profile and you are already off to a good
start. And maybe there's a picture from some marathon you participated in, and
they might have an online list of participants, narrow down to matching first
names, then look them up on facebook.

What facebook then sees mimics person A trying to find his new friend person
B, which makes it natural to include this person on the other "do you know
list"

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amelius
This is why I want the ability to "sandbox" my apps, so even though they might
want to have access to e.g. my telephone numbers, they can't because the
sandbox will hide them.

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wodenokoto
I'm getting tired of how aggressive Facebook is at suggesting new friends.

Facebook sends me phone notifications telling me they've found someone I might
know. I get it if it was a new profile and they want the ball rolling, but I
have over 900 friends on Facebook already, many I can barely remember where
I've met. Why do I need more people I barely know?

What is it that makes Facebook think their app is more engaging if my friend
list if full of people I barely know and never interact with?

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monochromatic
The Facebook app on iOS isn't listed as having requested access to my
contacts. Is this just an Android thing? Or does the app have some way of
sneakily getting access?

~~~
grrowl
Contacts is accessible by "Messenger" on mine, the Facebook app itself doesn't
provide contact sync.

~~~
monochromatic
Ok, that makes sense. I don't have Messenger installed.

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unfortunateface
Facebook App copies your phone book.

Facebook App copies your matches phone book.

Facebook finds that your phone book contains your matches number and vice-
versa.

Facebook suggests your match as a friend and vice-versa.

Nice and simple.

~~~
r3bl
Exactly. This article basically just talks about how you gave the permission
to an app to use your address book and then complains that it's using your
address book to identify who you should add as a friend. It's your fault for
agreeing to install an app that requests these permissions without
understanding why it needs those privileges from your smartphone.

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Krizzly
My husband told me that his customers show up as suggested friends on
Facebook. We always thought it had something to do with Whatsapp and Facebook.
Now I guess it's just because he uses the Facebook app on his work phone.
Crazy stuff!

~~~
harryf
At this point Facebook has enough data and capability to tell you not just who
you're dating right now but who you're likely to date in the future, based on
preferences and who you're likely to meet. They may not be doing it yet but
I'd assume it's at least been considered by them.

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werber
I've had this happen to me several times with guys I met on Scruff. It be nice
if there was an across the web ghosting tool for bad dates.

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newman314
I think this goes well beyond that. I've had FB suggest neighbors to me even
though we have never exchanged emails or friends etc.

~~~
morganvachon
That's simply down to proximity. Facebook, like Google, can tell based on your
GPS where "home" is (where your phone spends the night, basically) and it
knows the same about your neighbors. Your smartphone is a funnel for detailed
information about you to whatever apps you install on it, especially social
and communication apps.

Google in particular creeped me out with this kind of "feature". A few years
ago when I still used an Android phone, I changed jobs but didn't change the
information in any of my social media profiles, nor in my contact card on the
phone itself. After a few weeks, Google Now started giving me drive times to
work at the new work address instead of the old one.

~~~
dredmorbius
Question: what, if any, phone do you use these days?

~~~
morganvachon
I have an iPhone 6, and I'm seriously considering backing down to a non-smart
phone in the future. These days I mostly use it for SMS, voice, and very, very
light web browsing (basically HN and a few other news sites, and sometimes my
mobile banking site). I don't do apps, and the only really compelling feature
of the iPhone is Apple Pay. Now that my credit and debit cards are all
smartchip enabled, even that is just a gimmick.

In fact, I'd say the only thing keeping me on a smartphone at all is playing
Ingress, and my wife and I both are getting bored with it. Our local groups
are also playing less and less.

~~~
dredmorbius
Thanks.

I'd rightgraded to a feature phone, which often gets left off and/or at home.
I recently picked up a WiFi-only tablet. For much use, that's as much
connectivity as I need, though the ability to access a _very_ small set of
tools while in motion (mostly transit/navigation related) would be useful.
There I could get a 4G LTE wireless hotspot, and the price for both devices
and services is about right, but, as with the tablet itself, my concern is
_control_. I'm fighting Samsung for who's boss of my tablet (have yet to
root/re-ROM it), but for now, I most definately am not, and no, I'm not OK
with that.

A hotspot would have to support very extensive /etc/host blocklisting -- I've
grown quite fond of my laptop's 60k+ entries, and use of dnsmasq. Actually
starting to look at what I'd have to do to build and configure my own device,
though I'm not sure that'll happen.

Among other benefits, battery life for both phone and tablet is vastly better
than what I'd previously had for smartphone alone. Phone'll last a week,
tablet at least all day, heavy use.

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siliconc0w
The article has lots of words and stupid pictures so here is a summary: if you
give someone your number (via any app or medium) and they have the FB app
installed, it will recognize it as the number of a user and trigger the friend
suggestion.

The best way to handle the advent of this information is to treat your public
facebook profile as public information and assume even the creepiest
stalkeriest guy on the internet has access to it. Cause they do.

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Idontagree
Sounds like someone's lying.

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drugsAreBad0001
> He says this whole issue is mainly down to your phone number.

> Facebook goes through your phone book ... you give it permission to do this
> when you install the app.

This is 100% demonstrably false. It literally comes down to
advertising/tracking.

Because tinder is ad-supported for the free app, they're sending data directly
to advertising networks (of which Facebook is one), and that's being used to
track you. Period.

On iPhones an app specifically has to ask for permission to read your contacts
beforehand. There's nothing "implicit" about that, you literally have to agree
it explicitly.

I really wish the COO at a Security research company wouldn't spew nonsense.
And people wonder why the general public is misinformed as to the harm of
advertisers/tracking.

~~~
wodenokoto
Most phones are android though and there you have to give up your contact list
or simply not install the app.

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multinglets
Yeah, I haven't actually used facebook for anything in years, so now I'm
deleting my account and I will use a temporary phone for any future situation
where I need it.

I will also be going out of my way to spread as much FUD among my less tech
savvy friends as I possibly can.

Go Zuck yourself, Mark.

~~~
r3bl
Why don't you just delete the Facebook app from your smartphone? That way,
Facebook won't have access to your contact list. Therefore, this should not
happen.

I'm a casual Facebook user since like 2008, but I never even considered
installing any of the Facebook apps on my phone.

~~~
jzd
This is irrelevant.

You will still be tied to a unique identifier and tracked all over the web
because your browser fingerprint (yes, it's probably unique: test here
[https://panopticlick.eff.org/](https://panopticlick.eff.org/)) will be
reported back for every site affiliated with an advertising network affiliated
with Facebook.

~~~
r3bl
Not necessarily true with smartphones.

I just tried it out. The site acknowledges it tested out ~6M devices so far.
It's not that big of a number actually. My browser turned out to be unique
even though I'm using a pretty common method (basically just run Chrome on an
Android).

I've sent the version of Android (which was falsely detected because I
upgraded to a newer version, but I'm still sending the info about the older
version, so I'm assuming this is a bug), my Android model (and build) and my
timezone. Anyone who bought the same model from my country (and possibly even
the surrounding countries) would probably get the same fingerprint (unless
he's using a different browser).

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Animats
Facebook is fighting back. The drag queens didn't like Facebook's "real names"
policy. So Facebook is showing that it can infer the connections anyway.

