"And, they choose what to show us based on algorithms which learn from our personal data that they are constantly harvesting. The net result is that these sites show us content they think we'll click on – meaning that misinformation, or 'fake news', which is surprising, shocking, or designed to appeal to our biases can spread like wildfire."
He called for Facebook and Google to continue to combat the problem – Facebook announced tools to tackle fake news in December 2016 and updated Trending in February 2017, while Google banned 200 publishers from its ad network in January 2017 – and urged against the "creation of any central bodies to decide what is 'true' or not."
The personal information exchange
Berners-Lee also lamented people's loss of control over personal data. Free access to some websites comes in exchange for information that people do not mind handing over, he wrote.
"But, we're missing a trick. As our data is then held in proprietary silos, out of sight to us, we lose out on the benefits we could realize if we had direct control over this data, and chose when and with whom to share it."
Berners-Lee, who is a founding director of the World Wide Web Foundation and president of the Open Data Institute, criticized governments for monitoring what people do online.
"It creates a chilling effect on free speech and stops the web from being used as a space to explore important topics, like sensitive health issues, sexuality or religion," he wrote.
Political advertising is too targeted
Berners-Lee's third point relates to how online political advertising can potentially mislead voters.
"There are suggestions that some political adverts – in the US and around the world – are being used in unethical ways – to point voters to fake news sites, for instance, or to keep others away from the polls," he wrote.
"Targeted advertising allows a campaign to say completely different, possibly conflicting things to different groups. Is that democratic?"
The World Wide Web Foundation is to work on these issues over the next five years, Berners-Lee added. "It has taken all of us to build the web we have, and now it is up to all of us to build the web we want – for everyone."
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