Facebook has started notifying every user whose private data may have been compromised by the Cambridge Analytica scandal.

All 87 million of those affected (1m of whom are located in the UK) will get a message appear at the top of their News Feed notifying them and then giving them some next steps on how to protect their data in future.

In addition, all 2.2bn Facebook users will receive a notice titled “Protecting Your Information” with a link to see what apps they use and what information they have shared with those apps. If they want, they can shut off apps individually or turn off third-party access to their apps completely.

The Cambridge Analytica scandal started with an app called ‘This Is Your Digital Life’ – a personality quiz created in 2014 by a Cambridge University researcher called Aleksander Kogan.

The quiz paid around 270,000 people to take part, but thanks to Facebook’s data-sharing policy at the time, the app was able to vacuum up not just their data but all of their friends.

While Facebook later limited the data that these apps could access, the damage had already been done.

Since the revelations came to light Facebook has rolled out a huge wave of changes to the amount of personal data it shares with third-parties and has tried to give users more control over how they share their personal data with these apps.

How to check and delete the apps you have on Facebook

Head to Settings. This can be found in the top right-hand corner of Facebook’s profile page. Once within the settings menu head to the bottom left-hand corner of the screen and you’ll see the word Apps.

Once you click on this you’ll see every external app, or internal app, that uses Facebook either as a login or as a third-party service.

Click on any app and you’ll see exactly how much information about you this app has access to.

For example, “Cities I’ve Visited” was a simple map app I downloaded years ago to help track my holidays and share them with my friends. Yet when I look at what information I’ve shared with them, it’s almost everything including my birthday, education history, work history, current location, all photos including any that I’m tagged in and of course, my likes.

To bulk delete simply click on the box next to each one and you’ll be able to delete them all at once without getting any pop-up boxes for each one.

How to control what data you share with advertisers and others

While what we’ve just discussed can help you control what information you’re sharing through apps it’s not the full picture.

To get a complete understanding of how your Facebook information is being shared to advertisers head to Settings and then Ads.

From there you’ll be able to see why certain adverts are being shared to you and also control the amount of data that they can receive.

Finally to then control the amount of information you share with other people on Facebook head to Settings and then Privacy.