How Does Facebook Know Who You Know? People You May Know, Uploaded Contacts and the Setting to Change

Last checked: Oct 30, 2026. Based on Gizmodo reporting from Nov 7, 2017, Meta Help Center pages from 2026, and an FTC press release from Jul 24, 2019.

Facebook's People You May Know feature can suggest someone you've never met on the platform. Here's how it works, why it suggests people you didn't add as friends, and the settings you can change to limit who sees you in those suggestions.

#Watch: Who gave Facebook your number?

This video explains how People You May Know works and what you can do about it.

#How Facebook's People You May Know works

According to Meta's Help Center, People You May Know suggests people based on several signals, including:

• Mutual friends
• Groups, networks or workplaces you share
• Contacts you or others uploaded

The contact-upload connection is the one that surprises people most.

#The contacts others uploaded

When someone uses Facebook's Find Friends feature or turns on continuous contact uploading in the app, Facebook gets the names, phone numbers and email addresses from their address book, according to Meta's Help Center page "How contact uploading works."

Facebook uses those contacts to check whether each person has an account, and to power suggestions and invitations.

That means if someone else uploaded your phone number or email, Facebook may suggest you to them and suggest them to you, even if you never gave Facebook that information yourself.

#The shadow profile

In November 2017, Gizmodo reporter Kashmir Hill investigated People You May Know and spoke with users who were recommended people they only knew from contexts Facebook shouldn't have known about.

One attorney told Gizmodo that Facebook recommended "a man who was defense counsel on one of my cases. We had only communicated through my work email." The attorney believed Facebook was scanning her work email.

Gizmodo reported that Facebook isn't scanning work email, but it likely had her work email address on file, even though she never gave it to Facebook herself. The attorney's case was, according to a Facebook spokesperson, "the likeliest case for a shadow-profile connection."

Gizmodo and others call the result a "shadow profile", built from the contacts other Facebook users handed over. Facebook doesn't like or use that term, and says it doesn't create profiles for non-users.

But when users share contacts, Facebook holds on to all the contacts they handed over, according to the Gizmodo investigation.

#Contact chaining

If two people both have your email or phone number in their contacts and both upload them, Facebook may infer that those two people know each other.

"This is how a psychiatrist's patients were recommended to one another," Gizmodo reported. Facebook says there can be other explanations, such as mutual friends or shared networks, and won't confirm specific connections.

A Facebook spokesperson told Gizmodo: "Today, we use contacts uploaded to Facebook and Messenger to inform PYMK suggestions."

#How to change who can find you by phone number or email

You can restrict who sees your profile in People You May Know based on your phone number or email address.

Go to your profile picture, then:

1. Settings & privacy, then Settings
2. Under Audience and Visibility, click How people find and contact you
3. Next to People with your phone number, click View
4. Change the setting

#Your options

According to Meta's Help Center page "Control who Facebook can suggest your profile to based on your email address or phone number," the options are:

• Possible Connections: People who uploaded your phone number or email and your Friends of Friends (this is the default)
• Friends of Friends
• Friends
• No one: Your profile won't be suggested to anyone based on your phone number or email address

Repeat for email. The setting for People with your phone number is separate from the setting for People with your email address. Change both if you want to restrict both.

#What this doesn't stop

Even if you set both to No one, Meta's Help Center says plainly: "People You May Know may suggest your profile based on information other than your email address or phone number."

That includes mutual friends, shared groups, shared workplaces and other signals.

#How to delete contacts you uploaded

If you've ever uploaded contacts to Facebook or turned on continuous contact uploading, those contacts are still on Facebook's servers unless you delete them.

#Turn off continuous contact uploading

First, turn off continuous uploading in the Facebook app on every phone where you turned it on. According to Meta's Help Center, disabling contact access in your phone's settings does not delete contacts already uploaded.

#Delete uploaded contacts

1. Go to the Uploading and managing your contacts screen in Facebook settings
2. Select Delete All

This deletes contacts you uploaded. It does not delete or affect contacts other people uploaded.

#For people who don't use Facebook

Meta offers a form for people who don't use its products to check whether their phone number or email appears in Facebook's address-book database and to request deletion and blocking.

The form is at facebook.com/contacts/removal.

#What phone numbers from two-factor authentication are used for

In July 2019, the Federal Trade Commission announced a $5 billion settlement with Facebook. As part of the order, the FTC alleged that Facebook didn't disclose that phone numbers users gave for two-factor authentication were also used for advertising.

The order prohibits Facebook from using phone numbers obtained for security features, such as two-factor authentication, for advertising.

#The practical steps

1. Set People with your phone number to No one (or Friends if you want to stay visible to your friends' friends). Go to Settings & privacy, then Settings, then How people find and contact you under Audience and Visibility.
2. Set People with your email address to No one (or Friends), using the same path.
3. If you ever uploaded contacts, turn off continuous contact uploading in the Facebook and Messenger apps on every device, then go to Uploading and managing your contacts and select Delete All.
4. Know the limits: Other people's uploads can't be deleted by you. Other signals, such as mutual friends, groups and workplaces, can still produce suggestions.
5. Optional: Use a separate email address for social accounts. This is general privacy advice with no specific source claim, but it limits the reach of any one address.

#Why this matters

Facebook's People You May Know suggestions can reveal private connections, such as the psychiatrist and patient example reported by Gizmodo. Changing the settings limits one pathway for those suggestions, but it doesn't eliminate them completely.

UndoLeak erases your data from data brokers and keeps it off. Free scan.

#Sources

1. Kashmir Hill, Gizmodo, "How Facebook Figures Out Everyone You've Ever Met" (Nov 7, 2017). https://gizmodo.com/how-facebook-figures-out-everyone-youve-ever-met-1819822691
2. Meta Help Center, "Control who Facebook can suggest your profile to based on your email address or phone number" (2026). https://www.facebook.com/help/131297846947406
3. Meta Help Center, "How contact uploading works." https://www.facebook.com/help/917434021127849
4. Meta Help Center, "Delete contacts uploaded to Facebook." https://www.facebook.com/help/147699975301738
5. Federal Trade Commission, "FTC Imposes $5 Billion Penalty and Sweeping New Privacy Restrictions on Facebook" (Jul 24, 2019). https://www.ftc.gov/news-events/news/press-releases/2019/07/ftc-imposes-5-billion-penalty-sweeping-new-privacy-restrictions-facebook

Not affiliated with Meta, Facebook, Gizmodo or any company mentioned.