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Ask HN: How has Facebook figured out my family doctor as a friend suggestion?

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Re: Ask HN: How has Facebook figured out my family doctor as a friend suggestion?

#11

Post by compsciphd »

We've gone through this many times, its nothing nefarious.

1) doctor uploads his contacts (phone number/email addresses) to facebook and sets his contact info

2) you upload your contacts and set your contact info

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.

In other cases facebook can see you are friends with many of them same people and hence figures you might know each other.

Re: Ask HN: How has Facebook figured out my family doctor as a friend suggestion?

#12

Post by maccard »

greyman wrote: post #10
skdotdan wrote: post #3

Either you have searched you doctor, or your doctor has searched you.

I believe this is the correct answer, it happened to me as well. I got friend suggestion for my daughter speech therapist, and all our communication and appointments were done only in paper form. But I searched her name on FB out of curiosity. :-) OP: Can you exclude the possibility that the doctor just searched your name on FB? Why wouldnt he do that...?

> all our communication and appointments were done only in paper form

Just because your communication happened on paper doesn't mean that they haven't stored your email address or phone number in some service digitally, and that somehow that info has been shared (e.g. a phone with a facebook app that uploads all contacts)

Re: Ask HN: How has Facebook figured out my family doctor as a friend suggestion?

#13

Post by ams6110 »

simonduponte wrote: post #7

Factors that contribute to friend suggestions on FB: 1. Facebook tracking pixels on websites (if you visit a website with the pixel, you can be targeted in many different ways). 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. 3. Searching on FB, you say its unlikely for him to look you up on FB, yet theres always a chance that being…

I question point 2. Are you suggesting that Facebook reads my email? Have I given them my email password? If not, how? (I ask, because I don't use Facebook).

Sure, if we have each other's email addresses in our contact lists on Facebook, I can see how the connection was made.

Re: Ask HN: How has Facebook figured out my family doctor as a friend suggestion?

#14

Post by thawab »

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.

Re: Ask HN: How has Facebook figured out my family doctor as a friend suggestion?

#15

Post by patcheudor »

simonduponte wrote: post #7

Factors that contribute to friend suggestions on FB: 1. Facebook tracking pixels on websites (if you visit a website with the pixel, you can be targeted in many different ways). 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. 3. Searching on FB, you say its unlikely for him to look you up on FB, yet theres always a chance that being…

I'm glad you covered the bi-directional aspects of the association. A number of years ago FB had a vulnerability I discovered whereby it was possible to register an account with an e-mail you don't own. Obviously it wouldn't be possible to then verify the account if the owner of the e-mail targeted failed to click on the verify link. To get around this, upon first authenticating with the account after registration it was possible to change the e-mail address to one you own then send a very request. After verification, it was then possible to change it back to the original e-mail at which point it was verified.

In testing with a few people who never even had FB accounts and who I clearly did not import any contacts, etc., was that they fairly immediately received friend suggestions and even requests from people they knew. This was also despite the fact they'd never used the computer or even IP address used in the registration of the account. At the time it helped me prove a point that not participating in social media could be a security problem & to always take social media verification seriously. Obviously FB has since fixed that vector.

Re: Ask HN: How has Facebook figured out my family doctor as a friend suggestion?

#16

Post by [deleted] »

ams6110 wrote: post #13
simonduponte wrote: post #7

Factors that contribute to friend suggestions on FB: 1. Facebook tracking pixels on websites (if you visit a website with the pixel, you can be targeted in many different ways). 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. 3. Searching on FB, you say its unlikely for him to look you up on FB, yet theres always a chance that being…

I question point 2. Are you suggesting that Facebook reads my email? Have I given them my email password? If not, how? (I ask, because I don't use Facebook). Sure, if we have each other's email addresses in our contact lists on Facebook, I can see how the connection was made.

[deleted]

Re: Ask HN: How has Facebook figured out my family doctor as a friend suggestion?

#17

Post by hollander »

simonduponte wrote: post #7

Factors that contribute to friend suggestions on FB: 1. Facebook tracking pixels on websites (if you visit a website with the pixel, you can be targeted in many different ways). 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. 3. Searching on FB, you say its unlikely for him to look you up on FB, yet theres always a chance that being…

Using the wifi at the doctor's office would be another methods of linking. (I know this doesn't apply to the poster, but just giving another method.)

About 2: Email. I don't understand. If I send an email from my gmail address to his hotmail address, and both of us use the addresses for Facebook registration, how does that link us? And you say "either", so only one of us uses it for Facebook. I don't get it.

About 3: Maybe he has many links to other people on FB, people in his social circles, one or two or even three steps away. If you have enough of these people, the link is made. And they just show these people, and at some point you see it and all the others go unnoticed, but this one pops out.

Re: Ask HN: How has Facebook figured out my family doctor as a friend suggestion?

#18

Post by patcheudor »

ams6110 wrote: post #13
simonduponte wrote: post #7

Factors that contribute to friend suggestions on FB: 1. Facebook tracking pixels on websites (if you visit a website with the pixel, you can be targeted in many different ways). 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. 3. Searching on FB, you say its unlikely for him to look you up on FB, yet theres always a chance that being…

I question point 2. Are you suggesting that Facebook reads my email? Have I given them my email password? If not, how? (I ask, because I don't use Facebook). Sure, if we have each other's email addresses in our contact lists on Facebook, I can see how the connection was made.

In this scenario you don't know if the doctor uploaded their contacts list to FB. You further don't know if they are using a lousy e-mail app that sends usage information to FB, perhaps as part of an advertising integration.

Re: Ask HN: How has Facebook figured out my family doctor as a friend suggestion?

#19

Post by yjftsjthsd-h »

compsciphd wrote: post #11

We've gone through this many times, its nothing nefarious. 1) doctor uploads his contacts (phone number/email addresses) to facebook and sets his contact info 2) you upload your contacts and set your contact info 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…

I think we could reasonably disagree about whether or not it's nefarious. Siphoning everyone's contacts is iffy to start with.

Re: Ask HN: How has Facebook figured out my family doctor as a friend suggestion?

#20

Post by pmiller2 »

badthingfactory wrote: post #5

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. I'm not sure who I was most disappointed in. The hospital for purchasing the ad, Google for tracking my hospital visi…

And, to top it all off, those ads were utterly ineffective, since you'd already had the procedure done!

Amazon and eBay have this same problem, wherein they show you things similar to things you've already bought.

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