March 17, 2020 – Facebook offers lots of features like the ability to post photos, memes, videos or comment on other people’s posts or even chat with your friends. Facebook also goes one step further and actually suggests new friends to you when you’re on the site. But how does this work?

Facebook has denied that they are using location data to suggest friends, so where does this list of “people you may know” come from? Facebook’s media line on this, posted on their help page, is ‘mutual friends, work and education information, networks you’re part of, contacts you’ve imported and many other factors’. What makes it creepy is “…and many other factors.” Why is this so vague?

Here’s a statement from a Facebook spokesperson.

“Recode contacted us about a story on People You May Know and what information Facebook used to make friend suggestions. Among other examples, we were asked whether Facebook used information about who you call and text to make friend suggestions. We said that we didn’t, and we also explained that Facebook for Android app didn’t collect this information. At the time, people could choose to share this information with Messenger, but it was not used for People You May Know.”

These questions were asked by Vox to clarify the ‘Suggested Friends’ feature of Facebook:

Does Facebook use your location for friend recommendations?

No. Although, Facebook had used this method in the past, this is no longer used today. The platform insists that the case of the shared location was on coincidences. They supplied that the most likely explanation for this was that another person may have stalked or looking at our profile or may have recently added us to the contact list on their phone.

Does Facebook utilize my phone contacts to create friend recommendations?

Yes, they do. If you have shared your phone contacts on Facebook or Facebook Messenger, the company will accumulate this information to recommend your contacts as “Friends You May Know”. The only factor here is timing. This means that you will see a friend’s recommendation from someone you added to your phone recently, compared to the contact you have had for years.

Do both parties need to be saved each other’s contact info?

No, it does not need to. Whenever someone added your number on their contact list, you will see them on your “suggested friends” section even though you have never had their number on your contact list. To trigger this kind of recommendation, it only takes one user to do it.

Can Facebook see who you call or text?

No, they will not. The platform had said that they will not peek at who you call or text. 

Can Facebook see who you email?

They cannot. The site claims that their platform cannot see your emails. However, there is a caveat: Facebook relays the message that some email programs can automatically save your contact information to your mobile’s contact book whenever you emailed someone. This includes Gmail. You need to remember that Facebook can see your contact list if you share it, that’s why sending an email to someone could mean that they’re saved on your phone. Hence, this is used in friend suggestions.

What about web activity? Can Facebook see who I look at, like on LinkedIn and any other sites?

No, although the site does use web cookies to show you ads, it does not use web activity to recommend new friends. 

The explanation that seems the most obvious is that Facebook’s suggestions are informed by robust ‘link prediction’ and the modeling of its social graph.

Caitlin Dewey, a Digital Culture Critic in Washington Post, wrote last year that in the end, the platform’s feature ‘friend-recommending system’ isn’t magic nor malice. She added that it is purely good math.

Nevertheless, the users of Facebook can refuse the site’s use of their location setting in their phone’s privacy settings. Also, users can check if they imported contact from their phone to Facebook and request to have these removed on their ‘invite history’ page.