The creator of the worldwide web warned today against the collection of users’ data by commercial organisations.

Sir Tim Berners-Lee said that third parties, including companies and governments, should not be allowed to snoop on the public's browsing of the internet.

He told a meeting at Westminster: “We use the internet without a thought that a third party would know what we have clicked on. But the URLs / people use reveal a huge amount about their lives, loves, hates and fears. This is extremely sensitive information.

“People use the web in a crisis, when wondering whether they have a sexually transmitted disease, or cancer, when wondering if they are homosexual and whether to talk about it,” he said.

He said that people would consider using the web at a moment of crisis in a different light if users knew that they were being monitored and the data would be shared with a third party such as an advertising agency.

“This information is very sensitive. I feel it should not be collected,” he added.

Sir Tim said that businesses would initially insist that information was being collected only for a limited purpose but he said that they would be under enormous pressure to release it. “Once it exists, it can be used by the company or by an insider.”

Sir Tim, speaking at a meeting at Westminster organised by the Liberal Democrats to discuss the commercial use of data on the internet, said: “It should not be collected in the first place.”

There have been trials monitoring of the internet use of about 30,000 people to send adverts tailored to the users’ search interests. The development of advertising based on consumers’ internet usage is alarming privacy campaigners.

Dame Wendy Hall, a professor of computer science at Southampton University, appealed to Parliament to protect internet users’ privacy.

“There are lots of good reasons why companies and government want access to our data but there are huge downsides to that,” she said. “This debate is about our digital lives. It is about who we are, what we are interested in and what is private to us.”

Explore Tech & Web

• Personal Tech

• The Web

• Gadgets & Gaming