Sharing your data online – what you need to know

18 July 2019

When you're online, you will usually share some information about yourself, also known as your data, with the websites and services you use.

This data can be used in lots of ways. Mostly, it’s done to help improve your online experience. But it’s helpful to know about all the possible uses and how to protect your data from being used and shared in ways that you’re not happy with.

Ofcom’s purpose is to make communications work for everyone. Our Making Sense of Media programme is how we fulfil our duty to research and promote media literacy, including promoting an understanding of what is happening online. Understanding how and why your data is collected and used can help you to make informed choices and stay safe online.

Going online means making decisions about your data

Every time you visit a website, use an app on your phone or tablet, or even use a smart TV or other home device that connects to the internet, you are making decisions about how to share your data, and who with, even though you might not be thinking about it.

As well as the occasions when you provide data directly and knowingly, for example by filling in an online form, some websites and services collect data based on how you use them. When you visit a web page, your web browser might download and save small pieces of information known as ‘cookies’. These can be used to identify you as you visit different pages or sites.

Filling in an application form, scanning a loyalty card or searching the web on your mobile phone will contribute to your digital ID.

Your data can also be bought from third parties. This can happen when your data is publicly available, or when you have provided consent for companies that collect your data to share it. Your data can also be processed to make predictions about information you have not provided, like your income or your interests. In the UK, online service providers must have your consent or other legitimate reasons to process your personal data under the General Data Protection Regulation.

Some services wouldn't work properly without your data

Some websites and services rely on your data to work well. This could be a social network storing the contact details that you and your friends provide so you can communicate with each other, an online store collecting your address during a transaction to know where to send your purchases, or a taxi app collecting your location so that it can tell the driver where to pick you up.

Your data helps to improve and personalise services

Online services might use your data as part of improving or personalising the services that you use. For example:

  • when you allow search engines to know your location, they may use it to help you find shops or services in your local area;
  • by recording what you have previously watched, listened to or liked, some online services can make recommendations for you based on your interests; or
  • some online services use your data to make improvements, for example making them easier to use.

Online services can use your data to make improvements or make personalised recommendations.

Some online adverts are targeted using your data

Some websites, apps or services display ads to users. These can help websites make money, which sometimes means they can offer themselves as free to use.

Usually, the ads you see will be chosen specifically for you, using your data to work out which ads are most likely to appeal to you. This can include information about products you’ve previously bought, websites you have visited, products you have browsed and even predictions about your interests.

This is called targeted advertising and it means different people are likely to see different online ads, and sometimes the same ad might seem to follow you around online.

Targeted advertising means that different people are likely to see different online ads, based on their previous activity.

Taking control of your data

If you have concerns about sharing your data, it can help to understand your rights. The Information Commissioners’ Office is the UK's independent body set up to uphold information rights. Its ‘Your Data Matters’ information sheets have information that could help.

More information

There are several websites that provide advice about data that you might find useful.

  • Which?’s Personal Data website includes guides on your data protection rights; how to put a stop to unwanted communications; and how to manage your privacy settings.
  • The London School of Economics has launched My Data and Privacy Online, a toolkit aimed at younger people. This includes information on what personal data is being collected and why, and the steps you can take to protect your privacy online.
  • The NSPCC and O2 have teamed up to launch tips and advice on keeping children safe online including how to talk to youngsters about being ‘share aware’; how to set parental controls; and how parents can keep up to speed on the latest apps and games that their children might be using.
  • Age UK’s Internet Security website provides advice for older people covering topics such as online scams;  how to protect your computer;  and how to protect your privacy on social networks.