Sir Tim Berners-Lee, the inventor the World Wide Web, has issued a warning about its "negative consequences" on the 30th anniversary of him first proposing it to managers at CERN.

On 12 March 1989, Sir Tim wrote his proposal for a new information management system connecting documents held across multiple computers at CERN, where he worked as a contractor.

Vague but exciting, was the response of his supervisor, scrawled on the cover of the document.

It turned out to be a laconic greeting for an invention which would transform the world’s economy – and its society too.

The web has become a public square, a library, a doctor’s office, a shop, a school, a design studio, an office, a cinema, a bank, and so much more, Sir Tim wrote.

However, the web has also created opportunity for scammers, given a voice to those who spread hatred, and made all kinds of crime easier to commit, he added.

The inventor said that the Cambridge Analytica scandal at Facebook was one of the biggest news stories which had shaken people’s faith in the web.

In his letter he wrote: I broadly see three sources of dysfunction affecting today’s web: Deliberate, malicious intent, such as state-sponsored hacking and attacks, criminal behaviour, and online harassment.

System design that creates perverse incentives where user value is sacrificed, such as ad-based revenue models that commercially reward clickbait and the viral spread of misinformation.

[And] unintended negative consequences of benevolent design, such as the outraged and polarised tone and quality of online discourse.

Part of the blame for these things did fall to the web giants, the corporations which privately dominate so much of the web space.

Companies must do more to ensure their pursuit of short-term profit is not at the expense of human rights, democracy, scientific fact or public safety.

Platforms and products must be designed with privacy, diversity and security in mind, Sir Tim added.

He referenced the walkout by Google workers over the treatment of female employees there, and said: This year, we’ve seen a number of tech employees stand up and demand better business practices. We need to encourage that spirit.

However the most important of all possible responses to prevent the web turning bad, according to Sir Tim, was how its users behaved.

Citizens must hold companies and governments accountable for the commitments they make, and demand that both respect the web as a global community with citizens at its heart.

If we don’t elect politicians who defend a free and open web, if we don’t do our part to foster constructive healthy conversations online, if we continue to click consent without demanding our data rights be respected, we walk away from our responsibility to put these issues on the priority agenda of our governments.

(c) Sky News 2019: Web inventor Sir Tim Berners-Lee warns of ‘negative consequences’