Website owners should be banned from sharing personal data about its users with advertisers, a report has recommended amid growing concern over people’s privacy online.

During the 12 days of Christmas, more than 2,000 profiles of every internet user in the UK will be sent out to hundreds of advertisers, totalling at least 118 billion for the UK, according to analysis by British think tank New Economics Foundation.

Internet giants such as Facebook and Google rely heavily on advertising revenue for their businesses.

Although users agree to share this data by accepting their terms and conditions, it is thought that many people do not actually read them.

“Our digital selves have become marketable products and large companies are collecting and sharing data, our data, to make a profit at any cost,” said Duncan McCann, researcher at the NEF.

(Yui Mok/PA)

“Until legislation catches up, the adtech industry and the tech giants will use increasingly invasive services to advertise to us while compromising our data.

“This is a critical moment where we must intervene to ensure that the core business model of the digital age is not centred on ubiquitous surveillance and the provision of personalised advertising.

“Our proposal will disrupt the business model of big tech and force companies to use our personal data responsibly, without compromising our privacy.”

The report, Blocking the Data Stalkers, details how tech firms use bid requests for advertisers to assess the value of showing an advert whenever a link is clicked.

It warns that the information generated about a person when they click on a link could include sensitive information such as their sexuality or political beliefs.

The think tank also claims that there are loopholes in the General Data Protection Regulation (GDPR), which was introduced in May to address data protection and privacy.

It argues that the law is flawed because it requires individuals to take action, such as giving consent or lodging a complaint with the watchdog, the Information Commissioner’s Office.

In 2018, 44% of all advertising spend will be online – estimated to be worth 237 billion dollars (£187 billion), rising to over 50% by 2020.