I never use Facebook on my phone so you can hopefully rule out contact list networks - not that I ever had their personal mobile on my list - and location tracking because I haven't attended my doctor's surgery in years. We have zero friends in common. Other than my doctor actively looking me up on Facebook - highly unlikely - how on earth is this possible? I'm willing to accept friends of friends suggestions but this is beyond spooky.
We've gone through this many times, its nothing nefarious.<p>1) doctor uploads his contacts (phone number/email addresses) to facebook and sets his contact info<p>2) you upload your contacts and set your contact info<p>if there's one match between them, facebook believes (correctly) that there is some sort of existing relationship between you. The fact that its professional and not personal and you want facebook to just be personal doesn't change it.<p>In other cases facebook can see you are friends with many of them same people and hence figures you might know each other.
Factors that contribute to friend suggestions on FB:<p>1. Facebook tracking pixels on websites (if you visit a website with the pixel, you can be targeted in many different ways).<p>2. Email. If you have sent or received an email to the doctor, and either of you has associated that email to FB, you can be tracked.<p>3. Searching on FB, you say its unlikely for him to look you up on FB, yet theres always a chance that being a family doctor, he might have at some point seen one of your family member's FB and stumbled upon a picture or post in which you were tagged.<p>4. Whatsapp Contacts. As you know, Whatsapp and FB are part of the same company, hence have access to linked information. If you share certain Whatsapp contacts, a connection can be inferred.
I had a surgical procedure done at the beginning of the year. I hadn't explicitly shared this information at any point online or visited any websites related to the surgery. A few days after visiting the hospital for some tests, Google AdSense was showing me ads for surgeons at that specific hospital.<p>I'm not sure who I was most disappointed in. The hospital for purchasing the ad, Google for tracking my hospital visits, or myself for trading privacy for the convenience of services like Google Now.
The problem with all of these mobile apps is you just need ONE of your contacts to upload your information, and then you're fucked. That's why I've given up trying to hide my details because they already have it. The idea that all 100% of my contacts respect my privacy is ridiculous unfortunately.
I had something similar happen with an odd friend. I discovered that I shared my address book with the messenger app. With gmail auto-adding contacts, you might have been linked that way.
Possibilities:<p>1) you have instagram or whatsapp and use them frequently<p>2) you use an app that has Facebook login, that has location access or just has the SDK lying in app but not being used.<p>3) I don't know about what access react native/js frameworks have in terms of device resources, but that "may be" an another source of info leak.<p>4) your contacts/friends uploaded a photo on one of these services where you were there in the photo<p>5) if any of these apps have microphone access (when you record videos) it's "possible" to do many surreptitious things.<p>All of the above, done by 1 or many of your friends/contacts on Facebook/instagram/WhatsApp, FB identified you and correlated it somehow.
Facebook suggests a person I keep seeing on my commute that also works in the same building as me (not same company). I always think the 0 mutual friend recommendations are a bit weird/interesting
I think Facebook also connects people who appear at the same wireless access points, so you could have received the suggestion once your phone connected to the Internet at the doctor's office.
The most unusual friend suggestion I have received is a profile for the actor Steve Martin. It had two mutual friends, and appeared 20 minutes after a friend asked me "Have you ever listened to Steve Martin? The actor? He's also a bluegrass musician" and played a couple of songs on Spotify.<p>Any ideas on how that came about? It's hard to believe it's anything other than some app listening to audio.
Something is indeed spooky with Facebook and their other products. I am friend with a guy on Facebook and a person with the same name ended up as a suggestion on Instagram - ok maybe not so spooky. But(!) this guy looked like my friend except like ten years older. So I guess the combination of same name + looked like my friend (Facebook Face recognition) made Instagram suggest this dude to me.
I have a similar, but even less connected case than a doctor: a contractor that worked on my basement. No friends or clients in common that I know of. I've never been to his office. Don't even know what town he lives in. I did use FB on mobile for a short while, but probably didn't allow location info (call me paranoid). I most definitely did not upload any contact list.<p>How can it be?
How many other people in their recommendations list do you either not know at all, or only know of them, but have never met? Whatever algorithms they use to produce these recommendations (your social graph, IP addresses in common, etc) will of course wind up surfacing a broad range of people, including some back you actually know.
A Twitter acquaintance had a phone call from a website owner where he'd just browsed their site, no relationship in any other way.<p>We <i>think</i> they did a whois on his IP address which was at his company address, which we all know is doable, but seeing companies proactively do this is crazy.
May be due to <a href="https://en.wikipedia.org/wiki/Six_degrees_of_separation" rel="nofollow">https://en.wikipedia.org/wiki/Six_degrees_of_separation</a>
the facebook/messenger app upload all contacts. if he has your phone number, and your facebook account is registered with the same number, you will see a friend suggestion.
i don't use any of facebook's app on my phone and a few time's i see a freind suggetion of people i just met in a week or less.