Sunday 22 July 2018

The data machine: What Facebook knows about you - and how it uses your information

A figurine is seen in front of the Facebook logo in this illustration. REUTERS/Dado Ruvic/File Photo
A figurine is seen in front of the Facebook logo in this illustration. REUTERS/Dado Ruvic/File Photo
A 3D-printed Facebook logo is seen in front of displayed stock graph in this illustration photo. REUTERS/Dado Ruvic

James Titcomb

THE Cambridge Analytica scandal has been one of the biggest crises to hit Facebook and its chief executive Mark Zuckerberg since the company was founded 14 years ago.

But the episode has also led many users to re-evaluate their relationship with the social network, and question exactly what they are sharing.

Facebook's app and website use a multitude of data points and sources to obtain information about its users. While that data is never sold on, it can be shaped, prodded and moved to build up a picture of users that is far more detailed than what they might expect - or believe they have given away.

The social network's data targeting can often be so effective that users believe the app is eavesdropping on their conversations - a claim that has been repeatedly denied. The truth is that its data is so effective it has little need to listen in.

This week the company has been under fire over a feature that allowed apps - third party software that connected to Facebook such as quizzes, games and website logins - to gain access to the personal details of users' friends.

This was allegedly used by Cambridge Analytica to target voters in Donald Trump's election victory of 2016.

The social network revoked the feature in 2015, but this has far from shielded the company from criticism over the ways it collects information such as contacts, location and your web browsing data outside of Facebook.

A 3D-printed Facebook logo is seen in front of displayed stock graph in this illustration photo. REUTERS/Dado Ruvic

Advertisers receive no data from Facebook and third-party apps only receive it with permission. However, many still feel uneasy about the way the information is used, with events of recent days provoking a #deletefacebook backlash.

If you are concerned about Facebook's data collection, you can control what it collects on you by checking third party apps, limiting location and being careful about what you like.

So what does Facebook know about its users and how is that information important to the company?


What Facebook collects: It asks for access to your smartphone GPS signal, but also uses Wi-Fi connections, information you’ve entered about your hometown and address, and your IP address to determine your location.

What this is used for: Advertisers can target ads at people who live in a particular location, from countries down to individual postcodes. Companies can even target tourists in a certain area by comparing their current location with their hometown. Apps that use Facebook can see users’ hometowns and current cities. Nearby friends can also see where you are if you activate this in Facebook’s settings.


What Facebook collects: “Likes” include the statuses and photos you have liked, but also pages that you follow – from films to celebrities and football teams.

What this is used for: Facebook uses likes to determine your interests, which advertisers can then target with ads: an interest in Star Wars might mean adverts for a local cinema for example. Installed apps can also gain access to your interests, depending on your privacy settings. There have been concerns that likes can be exploited to target personality types: research has shown that liking particular things can give away your religious and political beliefs in addition to your taste.


What Facebook collects: If you have shared your phone’s address book with Facebook it collects those names, phone numbers and nicknames, contact photos, relationships and more. It has also taken these details from WhatsApp, although not in Europe. Even if you have denied it this data, your friends may have shared your contact details with their data settings. Facebook also has information on who you are friends with and any special relationship details, such as your romantic partner.

What this is used for: Everybody with a Facebook account, and many without one, has a “shadow profile” gleaned from this information. It is largely used to suggest people you may know, which has resulted in some bizarre situations such as long-lost relatives being found. Facebook apps were once allowed to gather information about a user’s friends as well as their own data – but Facebook pulled the feature in 2015. Advertisers can still target the friends of somebody who has liked a product or company page.

*Your web history

What Facebook collects: Thousands of websites have plugin “like” buttons that send data back to Facebook every time you visit them, even if you don’t interact with the button.

What this is used for: If you are logged in to Facebook, your browsing history is matched with your Facebook account to show you adverts based on your web history. Users can also be tracked even if they have logged out.

Facebook Founder and CEO Mark Zuckerberg speaks on stage during the annual Facebook F8 developers conference in San Jose, California. REUTERS/Stephen Lam/File Photo

*Apps you install

What Facebook collects: If you have clicked that useful “log in with Facebook” button instead of coming up with a username and password, you are telling Facebook something new about you.

What this is used for: The apps you install are used to create a picture of what you are interested in. Advertisers then target these interests.

*External data

What Facebook collects: Facebook buys information from data companies such as credit ratings agencies and Dunnhumby, the operator of Tesco Clubcard.

What this is used for: Facebook uses the information to build up a picture of your interests and of your demographic, which advertisers can then zero in on when targeting adverts. There are dozens of different buckets Facebook can put you into, from the year your car was bought to your credit card type to your salary bracket.

Read more: Here's how you delete a Facebook account - but are you willing to do it?

Read more: Facebook boss admits 'mistakes'

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