… but we are all Facebook users | Hacker News Reader

… but we are all Facebook users

blog.onyxbits.de

41 pointsmistytoe12 comments

For those on cable service with long lasting IP addresses..

You don't use FB, right? But you let your friend you your wireless off his phone, and he had the FB app and location services on. Well, FB now knows exactly where your IP is, for a while at least.

No. I block all FB domains at the router, and force all dns requests to redirect to it.

Doesn’t matter. As long as a single smartphone with GPS enabled roams past your WiFi (and sees its advertised MAC address), any app on the phone can associate the user’s GPS coordinates with your router’s MAC address. Do this with enough users, and enough routers, and you’ve got a nearly perfect geographical mapping of WiFi routers.

This isn’t a conspiracy; Apple and Google have been doing this sort of triangulation for a long time, and even use it as a method of saving battery while avoiding the GPS radio.

Any app on your phone, including the Facebook app, can see nearby WiFi networks (maybe this is a gated permission now?). If the app has enough users with GPS enabled, its developer can easily build a GPS/WiFi map.

Well what you described has absolutely nothing to do with GP's premise, and to which I was replying:

> But you let your friend you your wireless off his phone, and he had the FB app and location services on. Well, FB now knows exactly where your IP is, for a while at least.

https://wigle.net/

> Courtesy of every idiot who (illegally) uploaded their addressbook, with my contacts in it, to the service.

I know your address is PII, but seriously it's illegal to upload that info to FB? The post office does this with your snail mail info, and anybody could pick up a discarded envelope at the dump, or see a forwarded e-mail message with your address in it.

I am not saying that people should be blithely uploading their address books, but is it illegal?

And, come to think of it: does google track the address graph of gmail users? They could do this entirely with envelope information (SMTP MAIL FROM and RCPT TO), though message headers would be a richer trove.

In Germany it probably is, technically. It's of course unlikely to have consequences for the individual user (I'm only aware of a single court case regarding Whatsapp doing the same, and that wasn't even a privacy case at the core), it's more something people are going to go after the service for. You are sharing private data with a company that you haven't been authorized to share it with, and non-registered users have no agreement with the company of their own which would allow it.

> but seriously it's illegal to upload that info to FB?

In Germany, it is.

Relevant quote from the Whatsapp TOS (Whatsapp belongs to Facebook):

> Address Book. You provide us the phone numbers of WhatsApp users and your other contacts in your mobile phone address book on a regular basis. You confirm you are authorized to provide us such numbers to allow us to provide our Services.

Relevant german court order:

http://www.lareda.hessenrecht.hessen.de/lexsoft/default/hess...

It's a bit lengthy (and difficult!) to translate. In summary it's a child custody case about excessive smartphone use in which the court orders the mother, among others things (limiting smartphone usage) to get written consent from all contacts in the child's addressbook. The issue is that in Germany, your contact data is "copyright" be yourself. You don't have to put up with people freely resharing your contacts and theoretically, the child could have been "sued"(+) by anyone in the addressbook who isn't also a Whatsapp user.

(+) There is a "light version" of "sueing someone" in Germany, called "Abmahung", which is frivously used by some law firms.

lol "illegally uploaded contacts" contacts are public knowledge. you dont want someone to share it dont give it to that person .

What's your full name, phone number, email address, and home address? Or alternatively, how do your presumably extant friends know how to get in contact with you, given your impenetrable policy of never sharing any contact information?

I give this information to my friends, I do not expect them to share it with the rest of the world. If someone who knows of me from a common friend wants to contact me they can ask that friend to pass on their contact details to me.

The author's domain ends in .de so I presume he's German. Attending a data protection lecture in Germany, the lecturer said the same thing, he can technically sue his friends because they gave his name and number to a 3rd party, without his consent. So at least in his jurisdiction it's illegal, however you may disagree.

Tragically even "secure" apps like Telegram does this.

The more interesting aspect is that if a group of people, some of whom are friends, uploaded their contacts, the network (Facebook, WhatsApp, Telegram) can build a graph of friends. And they can build a profile of you based on the profiles they have from your FB-using friends. Not sure how exact it'll be, but it's what they do and sell to their customers.

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