Being tracked online is an inevitability of modern life. Whether it's companies looking to weigh up your interests and tantalise you with targeted advertising or those gathering user data to help shape their own products and services, your online activity is of great interest to many - and none more so than Facebook.
But even though most people are aware that this happens, it's still surprising to discover the degree at which we're being tracked, and the sheer volumes of data that's being held.
We asked 1,367 users who said they used Facebook at least once a day to check their settings, and the average number of websites or apps that Facebook reported tracking them on was 283. Some 82% said this was higher than expected and 84% were surprised by some of the types of organisations that Facebook tracked them on.
5% of users found more than 1,000 websites or apps in the list - figures that would startle all but the hardiest of social media users.
If you're uncomfortable with this, then fear not - there are some fairly simple steps you can take. Somewhat buried in your Facebook settings is a dedicated tool called 'Off-Facebook activity', that allows users to disconnect the information gathered about them from online tracking on websites and apps not owned by Facebook. It won't stop you being tracked, but it will essentially anonymise the data, which you may feel is better than nothing. There are also ways to get a view of how you've been tracked so far, if you're brave enough to take a look.
One of the main reasons you're tracked is so that organisations can show you adverts that are more relevant to you, via platforms such as Facebook. And our research found that 32% of respondents do, at least sometimes, find adverts on Facebook useful, although 34% say that they always ignore them.
Currently, if you don't like targeted adverts, you can't fully turn them off and choose instead to receive ones that don't require the collection of your data. However, the Competition and Markets Authority (CMA) have said that this should change.
Over the past year, the CMA has been investigating digital advertising on online platforms, including Facebook and Google. As a result, it has recommended a number of interventions to give consumers more control over their data. These include that platforms should be required to give consumers a choice over whether they receive targeted advertising - if consumers choose not to have targeted adverts then they would receive adverts which would be based on much more limited data.
Which? has written to the newly formed Digital Markets Taskforce, who will take charge of moving these recommendations forward, to fully support that consumers should be given a choice over whether they receive targeted adverts. In the meantime, there are steps you can take to better control your data by adjusting your Facebook settings.
One way Facebook collects information about you is by observing what you do on Facebook and Instagram (which Facebook also owns) and from your profile information. If you have accounts with both, information about what you do on Instagram will influence what you see on Facebook. Facebook then uses this data to try to make the adverts you see at Facebook more relevant. It collects information on things such as:
By collecting this information Facebook can work out things such as your age, gender, location and what your interests are. This is then used to target you with adverts that Facebook thinks you'll be interested in.
Generally, people are pretty clued up about this - just 8% from our survey weren't aware that Facebook collected any information about their activity on its platforms to target adverts and 92% said they were aware of at least some of it. As for how they felt about it, people were divided - 54% felt it was at least somewhat acceptable, but 44% felt it was at least somewhat unacceptable.
Facebook also collects data about you from other organisations it has a relationship with - it uses this data to try to make the adverts you see on Facebook more relevant.
One of the ways it collects information from these organisations is to track your activity when you're on their websites. They do this using a 'Facebook pixel' (which is like a cookie) or if you log-in using your Facebook log-in.
Information is sent back to Facebook about web pages you've looked at, whether you've purchased something or put something in your online basket.
In our survey, just 19% said they were aware that this happened and knew how it worked, 47% said they knew about tracking but not the mechanics of it and 34% said they had no idea at all.
If you're intrigued enough to want to check your own Facebook profile, it's fairly easy to do.
Follow the steps below to access your tracking settings on a desktop computer. The steps may vary if you're logging in with a mobile device, or through the app.
Another way that Facebook collects data about you to target its adverts is by matching your Facebook profile to customer lists provided by an organisation to Facebook.
A customer list tells Facebook that you have engaged with this organisation in some way, but Facebook gets no more information than this.
Organisations upload information such as your phone number or email address via a customer list and this can be matched to your Facebook profile. These lists are put into code so that your details can't be seen by anyone, but a computer programme can tell if the details match a Facebook profile.
You may be on an organisation's customer list if you signed up for an email newsletter, made a purchase at a retail shop or signed up for a voucher or discount.
Some 79% of those in our survey were not aware that Facebook matches profiles to customer lists to target adverts. Whether or not you're in that group, you may well be intrigued enough to have a look for yourself.
To find out what organisations Facebook has matched your profile with using a customer lists, follow these instructions:
If you're surprised by some of the names you can see here, you're not alone. In our survey of users who said they used Facebook at least once a day, 82% said this was higher than expected and 84% were surprised by some of the types of organisations that Facebook tracked them on.
Of all the 1,729 Facebook users we surveyed, only 11% were aware of the Off-Facebook activity tool, so there's a good chance you haven't heard of it either. 'Off-Facebook activity' gives you the option of disconnecting from your profile the information that Facebook has gathered from tracking you on other websites/apps. You also have the option to stop Facebook connecting your account to any information it gathers in the future from online tracking on other websites and apps.
Both of these actions can be taken for all websites/apps, or you can choose which you want to take the action for.
To explore your options further, or if you decide to use the Off-Facebook setting, follow the steps above to get to your Off-Facebook activity page (under How to check Facebook tracking), then:
A survey of 1,729 adult Facebook users in the UK was conducted online by Populus, on behalf of Which?, between 23 June and 9 July 2020. Quotas were set on age, gender, region, education, social class and frequency of Facebook use based on the demographic profile of Facebook users estimated by a previous Which? survey.