I am 99% sure LinkedIN used my IP address to match with my second floor neighbor, despite their claims that they would never use IP address as a connection data point.
I was sharing my wifi for a brief period with my neighbors on the second floor. My neighbor had a new room mate. The guy was from another country. He didn't work in the same industry I do. I didn't have any of his contact information anywhere on any of my devices, and afaik, vice versa. We had no formal contact in any fashion, monetary or electronic communication or any other kind of contact other than passing each other in the hall. I didn't even know his name. He's just one of millions of people who live in my region.
Yet they suggested him as a possible contact.
If they weren't using IP address, they were using black magic.
edit:
to clarify, i forgot to mention that i had no linkedin connection to my neighbor, afaik he didn't have a linkedin account, he definitely doesn't have one currently. He was sort of a luddite, barely used his computer, and i don't believe we ever emailed each other, or even had each other's email, I just searched my mail and have record of any.
And I very much doubt my neighbor had any obviously traceable connection with the roomate anyway, at most a phone number and received rent through cash or check.
That's creepy. Different topic: I think the biggest connection business is whatsapp. If a person does not use whatsapp but a friend of that person does, whatsapp knows the person's phone number anyway. If >= 2 whatsapp users have that person's phone number stored with the same name in the contact list, whatsapp even knows the person's name (and other information). With that information they can accurately identify the person's facebook profile. Horror!
I think it was clever to remove Whastapp from my phone the day facebook acquired them. Sure, they can still connect my number to one of my fake profiles I used to have some years ago.
Are you connected on LinkedIn with your neighbor? Because if your neighbor was connected with him, that could be how it happened. I think it will show if any of your connections know him (up to 3 hops away), but you might need to visit his profile to see that info (I don’t use LinkedIn often but noticed that feature before).
linkedIn was suggesting people that were using the same wifi network as I was. I thought this was spooky — I could see more info about my hotel guests than they probably realized.
LinkedIn definitely uses same IP address to suggest connections. My wife as suggested connection really stood up in this way for many reasons (profile recently created, a few connections from the other side of the world and in a totally different industry).
So it would be even worse, they would need to retrieve a phone number in some way and match that. I don't register email contacts anywhere, and I am not using the LinkedIn app. I would say that I have seen similar things at work/work location (consultant). Seeing people with no shared contacts among the first ones in the suggested list. Until then I though it was related to 2nd or 3rd level of linkage.
I suspect that information can be obtained in ways other than IP addresses. Close enough to be the same thing, but enough distance to state, “we’re not tracking IP addresses”, and have their lawyers approve.
I knew a guy who worked in an industry where using SSNs for identifying people was illegal. Their solution was to prefix the SSN with a leading one. Compliance.
Before it is tested in court, every possible shade of grey looks blazing white to a group of people who mutually reinforce optimism and punish doubt amongst themselves.
It may be more complex than that. If both of you were tied into the Social Graph it's possible software on your devices simply knew the two of you were in proximity and for how long. This could be done via Bluetooth by an app like WhatsApp or Facebook, which is known to have sensors installed in urban businesses. But who's to say they didn't just turn your device into a beacon itself using the Physical Web?
I was sharing my wifi for a brief period with my neighbors on the second floor. My neighbor had a new room mate. The guy was from another country. He didn't work in the same industry I do. I didn't have any of his contact information anywhere on any of my devices, and afaik, vice versa. We had no formal contact in any fashion, monetary or electronic communication or any other kind of contact other than passing each other in the hall. I didn't even know his name. He's just one of millions of people who live in my region.
Yet they suggested him as a possible contact.
If they weren't using IP address, they were using black magic.
edit: to clarify, i forgot to mention that i had no linkedin connection to my neighbor, afaik he didn't have a linkedin account, he definitely doesn't have one currently. He was sort of a luddite, barely used his computer, and i don't believe we ever emailed each other, or even had each other's email, I just searched my mail and have record of any.
And I very much doubt my neighbor had any obviously traceable connection with the roomate anyway, at most a phone number and received rent through cash or check.