How can you stop Facebook accessing and sharing your personal information?

Facebook CEO Mark Zuckerberg has admitted mistakes and outlined steps to protect user data in light of a privacy scandal involving data mining firm Cambridge Analytica.

Mr Zuckerberg said that Facebook has a "responsibility" to protect its users' data and if it fails, "we don't deserve to serve you".

The 33-year-old has also been summoned by MPs to attend a parliamentary committee and give evidence about the use of personal data by Cambridge Analytica.

The British research firm are being accused of a data breach by using a "personality test" app to access user's personal information without their consent.

It is alleged that they used this information to create targeted ads in order to influence elections around the world, such as the one that made Donald Trump president.

Facebook is accused of doing nothing to stop this data breach, which was discovered by the social media giant in 2015.

But just what information does Facebook hold on you, how much of it was Cambridge Analytica able to access and what can you do to stop your information being stored and shared?

  • What does Facebook know about you?

As you probably know, when you signed up to Facebook, you allowed them access to a whole range of your personal details.

They hold information on you under 71 different categories, including the obvious things such as your name and date of birth and even every Facebook search you've ever conducted.

To find out exactly what information Facebook has on you, it is possible to download a copy of your Facebook data.

On Facebook's desktop site, simply hit settings on the drop down in the top right corner, then general, then at the bottom of the display, click on "download a copy of your Facebook data".

Click on settings from the drop down menu in the top right hand corner. Credit: Facebook

Due to the sheer mass of information, you are told by Facebook that there might be a considerable wait before your data is available to be downloaded.

Then click on General in the top left and hit 'Download a copy' at the bottom of the display. Credit: Facebook
  • How much of your info can apps access and how to stop them doing so?

You trusted Facebook wouldn't allow your data to be shared, but that wasn't entirely true.

Apps also have access to a whole range of the above info, and as we found out with the Cambridge Analytica scandal, those apps are able to share your info.

When you use Facebook to sign into an app, rather than creating an account, you give that app access to much of your Facebook data.

Although it is a violation of Facebook's privacy policy for apps to share this info, it is worth finding out just what info they have access too.

Again, click settings from the top right drop down menu, then click on apps, then click on the little pen icon next to the app to see how much of your info they are accessing.

Click on 'Apps', then click on the pencil icon next to the app to view and edit settings. Credit: Facebook

A typical app, such as accommodation site Airbnb, has access to a wide range of data.

This includes your public profile, your friends list, date of birth, education history, your home town, your Facebook likes and your email address.

You are able to uncheck certain aspects of the accessible information.

Some apps require you to share info in order for them to work, so if you don't want Airbnb to have access to your public profile, you will need to delete the app.

From here you can uncheck certain aspects of what information you are sharing. Credit: Facebook

Next, you can also see how much of your data is being shared by friends when they use apps.

Further down the page, click 'Apps others use'. Here you can stop all aspects of your data being shared by friends.

Click on 'Apps others use' to edit how much of your data your friends are sharing. Credit: Facebook
On this page you can edit how much of your data your friends are sharing. Credit: Facebook
  • How to get apps to delete your data?

Facebook says apps have access to your personal information so that they can tailor the experience to you.

Apps such as 'thisisyourdigitallife', the personality test app used by Cambridge Analytica to access info on 50 million Facebook profiles, may want your info for more sinister reasons.

At the moment, all you can do is ask the app to delete your data, however, when the European Union enacts its sweeping data protection laws, it will be illegal for a company to refuse to delete data when asked.

This is how to ask them; again click on the pencil icon next to the app and at the bottom of that page, click 'Report app'. Then click on 'I want to send my own message to the developer'.

Click 'Report App' at the bottom right of the display. Credit: Facebook

Then simply send them something like: "I would like any of my current data to be deleted from your database, and I revoke future access."

Click on 'I want to send my own message to the developer' and then send them a message. Credit: Facebook