How does facebook define People you may know?

Question

Facebook

After the second strange coincidence, I wondered by what algorithm facebook assumes that you can know a person (function people you may know)?
In his blog, FB writes that the function is looking for common acquaintances / common places of study and work, but:

Strange times: the wife did not communicate with a friend from Germany for more than 8 years. FB assumed she knew the man. General schools/places of work, etc. no profiles, no mutual friends/colleagues either.

Oddity two: yesterday the same thing happened to me - fb suggested that I know a person with whom I had not communicated for 9-10 years. Also, there are no mutual friends, there are no common places of study / work either.

The number of “friends” in the profiles of both her and me is no more than 50.
Help explain the strangeness.

Answer 1

You have friends who still have friends who still have friends, and there is this person. (well, or not friends, I have the same comparison of profiles through several friends).

Answer 2

It is possible that you, like your wife, studied / worked / lived with these people at the same time, and the profile data is similar in some period.
Or…

Answer 3

Email contacts?

Answer 4

Big brother is watching us…
Twice I received an invitation to FB, but I never registered…
And now the interesting thing: the invitations were from two different people who practically did not know each other (friends of friends of friends), the list of “possible friends” was accurate and included one person whom both of those who sent invitations do not know for sure - this is my lecturer from the university where I studied several years ago and on the other side of the country ...

Answer 5

Personally, FB constantly shows me in “hypothetical friends” one distant acquaintance who I have in VK friends. Moreover, I didn’t give access to Facebook anywhere ... So Big brother :) (well, or Google, which is the same thing)

Answer 6

I was always shown friends of friends, marked "You have N friends in common" + sometimes people from my city. I never gave an email login / password to Facebook (and indeed to any social network), so it’s unlikely by postal addresses.

Answer 7

Maybe there are mutual friends of the "second" circle.

Answer 8

I remembered a story from one of the sites
“Well, where does facebook offer friends from? I’m constantly offered to make friends with my husband’s mistress, even though I don’t know her ”(reproduced from memory)
And so I join the above - an analysis of friends / places of study / work / place of residence. + Search by mail\skype\etc obviously works in two directions.

Answer 9

Recent article on the topic: here

Answer 10

LinkedIn, for example, uses keywords.

Answer 11

I would really like to know the answer to this question. Recently, a friend of mine (does not use FB) gave me (I have an account on FB, but I don’t use it at all) a person’s phone number. I called him a couple of times, and then I go in, and there he is, "maybe you know each other." Explain how? What, fb traces contacts on the phone too (on calls)?
I don’t like Facebook at all, although I am an active Internet user

Answer 12

The same situation happened recently. In my case, WhatsApp was involved in the case, apparently when adding a phone to a notebook, whatsapp sends a command to add to facebook.