Who's watching me on the internet?

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1. Digital footprints

Around 40 million UK adults – 78% of us – go online every day or almost every day. By posting on social media, booking tickets or streaming a show, we add to the 2.3 billion gigabytes of internet data created daily.

The data trail we leave on our online journey says much about our habits and our tastes. This information is, of course, much in demand. The benefits of analysing personal data are becoming clear and many interested parties are already busy doing it.

But should we try to cover our footsteps? Do all those who monitor our online behaviour represent a threat to us, or can it benefit our lives?

2. How do I leave a data trail?

What we openly post on social media or in forums makes up part of our data trail.

We also share information about ourselves when we fill in name and address forms, create login passwords or store files remotely 'in the cloud'. All this should remain secure, but it doesn’t always stay that way.

And there's another almost imperceptible trail of data that we leave when we browse the web.

IP address

When we visit a website or send an email we leave a record of our Internet Protocol address. This is in effect our internet identity, the number assigned to the device we are using to go online.

Search terms

What we type into our search engine is logged by our Internet Service Provider and the search engine. Their records can help identify when we visited a website and where we were at the time.


Most websites download cookies – small text files – onto our device when we visit them. These help the websites recognise us when we return. Some cookies track our online activity so the adverts we see reflect our interests.


A keylogger covertly records what we type on our keyboard, which websites we visit and which applications we use. It might be installed by our employer or hidden in spyware that is unwittingly downloaded.

3. How can I protect my privacy?

To find out how difficult it is to avoid sharing data, Rory Cellan-Jones tries to spend a day without doing so.

4. Who is Citizen Four?

“For now, know that every purchase you make, every call you dial, friend you keep, site you visit and subject line you type is in the hands of a system whose reach is unlimited but whose safeguards are not.”

In June 2013, Edward Snowden – a former CIA employee calling himself Citizen Four – released thousands of classified documents from America's National Security Agency (NSA) to the global press.

The ongoing publication of leaked documents has revealed details of mass surveillance proving that the NSA and CIA can track your activity with the click of a button.

Nothing to hide

On 20 April 2016, a series of documents from MI5, MI6 and GCHQ were published, revealing how the UK government's intelligence services track and store information about each of us.

These files are kept on citizens that the agencies themselves acknowledge are "unlikely to be of intelligence or security interest".

The documents reveal the routine requisitioning of confidential information shared with doctors, including a person’s blood group, biometrics and even hair or eye colour.

GCHQ also has access to people's travel records, personal finances, purchases, internet feeds, phone calls, and even private communications with lawyers, MPs and government departments.

5. An upside to analysing my data?

Having people watching us isn't all bad news. Click below to learn how the data we share is being used to benefit both ourselves and the wider community.

Online experience

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Online experience

Regarded by some as intrusive, cookies enhance our interaction with our favourite websites and help create an internet experience tailored around our interests.

Crime prevention

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Crime prevention

Police in London have piloted software which analyses social media to try to predict which criminal gangs are most likely to commit violent crimes.

Healthcare benefits

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Healthcare benefits

Researchers in America have analysed Twitter output to try to learn more about the psychological health of a community and predict rates of heart disease.