An unfamiliar face catches your eye as you scroll down your timeline – someone you may know, according to Facebook.

Yet, on closer inspection you have no mutual acquaintances and there are no obvious links as to why this person has been suggested as a ‘friend’.

Exactly why did Facebook recommend this person to you? What information did it use to do so? And how can you limit the information available to it, should you so wish?

“Facebook wants people to spend the longest they can on the platform, so that their advertisers pay more,” says Jodie Cook, managing director of JC Social Media in Birmingham.

“Facebook uses any information it can glean from them, including locations, events, external apps plus anything else its algorithms pick up. There really is no hiding."

This week we will publish a series of articles throwing a spotlight on the social media giant’s use of data, starting with tagging and location.

Facebook failed to respond to two separate requests for comment.

Tagging

Facebook tagging

Tags on pictures or to show location both have influence over ‘people you may know’. If a friend tags you in a picture, Facebook then has reason to link with all others tagged in the same picture or album.

This also means the picture of you can be seen by people you don’t necessarily know, depending on the privacy settings determined by the poster of the photo.

“You can have privacy settings in place but if people tag you into photos it widens it up,” Pamela Hopkinson (pictured below), director of Social Media Solutions in Barnsley, told BusinessCloud.

Pamela Hopkinson

Location comes into play when you check yourself in – or someone else checks you in – at a place or event. “I was speaking at an event at the National Space Centre at Leicester and other people who had tagged themselves at the event were suggested as potential friends,” revealed Nik Hewitt, digital strategist at Tank PR in Nottingham.

If you tag a photograph with a location, that photo then becomes public and visible to all those who are searching for that place or who have used the same location tag, according to Carmen Lascu (pictured below), a social media expert and blogger based in Southampton.

“I tried this by publishing a photo of my daughter in a park and tagging the location, and when you searched for that park on Facebook my photo was there on the page,” she said, adding that this should be considered when using this feature.

“People think they’re sharing their location with their friends but by doing this they’re actually sharing their photo with the public.”

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Carmen Lascu

Facebook says it collects content and other information when people use its services, such as when signing up for an account, creating or sharing and messaging or communicating with others.

This can include information such as the location of a photo or the date a file was created, and the same details from people who tag you.

Location

Facebook location

Following rumours that the GPS location of a user’s phone was used, Facebook initially seemed to agree but then backtracked in 2016.

“That had negative undertones so they changed their position,” Hopkinson said.

However, there are cases where geographical location – where a user has not used a location tag – seems to be the only answer.

“There was a case where someone had gone to a support group for suicidal teenagers and one of the other members of the group had popped up afterwards in their ‘people you may know’ section,” she continued.

“That contradicted the argument of them not using it, but they’ve come out and said ‘no we don’t’ – although they don’t give a definitive list of what they do and don’t use.”

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There are other suggestions around the IP addresses of servers being used, Hopkinson added, which would possibly bring geographical information into play.

In its terms and conditions, Facebook says it collects information from or about the computers, phones, or other devices used to access the site. This includes device locations, including specific geographic locations, such as through GPS, Bluetooth, or WiFi signals.

However, it stops short at saying how it uses this.

Tomorrow: Focus on phone contacts and email account

BELOW: Flick through the Q1 2017 edition of BusinessCloud's interactive digital magazine

E-edition cover