Officially, Sir Tim Berners-Lee doesn't have a favourite website. When you're the creator of the World Wide Web, he says, "You can't."
"'What's your favourite website?' was the first question everybody asked," he says. "Sorry, I don't have one."
But, even if he's too honourable to show even a hint of favouritism, Sir Tim does occasionally have preferences.
One app he especially liked was an activity tracker called Moves, which he used to see what he'd been doing in his journeys round from his home in Massachusetts, where he is a professor of computer science.
Then, in 2014, Moves was bought by Facebook - meaning Sir Tim's data now potentially belonged to the world's biggest social network.
And then, earlier this year, Facebook shut down Moves. There was no appeal. Facebook simply announced that it was "moving on".
For Sir Tim, it was a personal taste of a bigger problem. The web he built was broken - and the big companies that dominated it were the flaw.
The awakening for him, as for so many people, came in 2016, with the twin shocks of Brexit and the election of Donald Trump.
"What happened there was a tipping point," he says.
He knew that social media could be used to manipulate people, but for the first time he saw it operating at massive scale.
"I thought that my responsibility as a web user was to go and find the stuff which I appreciated, which I trusted, but now I think that everyone involved in the web realises the problem is that other people are reading stuff which is complete garbage and they're believing it, and they vote."
He mentions voting. Does that, I ask, mean democracy itself is under threat?
"Science tells us what to believe are facts," he says. "And democracy relies on facts. So democracy relies on science."
Sir Tim sees the core of the problem as the massive centralisation of his originally decentralised web.
"Instead of going from website to website, everyone's on one website, so the structure of people making great links to other blogs which we had after 10 years of the web is more broken.
"People don't follow links from one website to another, they sit on one website, and what they see is determined by the people who code that social network."
Sir Tim is too polite to name the network, but there can't be more than a few candidates. Between them, four or five giant corporations dominate everything we do online.
It's with those sites - and governments - in mind that, last week, Sir Tim launched a charter for the web : a Magna Carta of digital rights.
Facebook and Google have already signed up, as has the government of France; although whether they abide by its terms remains to be seen.
He's also launched a new project: Solid . It's effectively a new web; only this time he's going to get it right.
The key change is to do with data. On Sir Tim's original web, users' data was - and is - stored by the owner of the website or the app.
On Solid, the choice of where you put your data is separate from your choice of service.
Your data - from your selfies to the money you send - is hived off into a separate area, called a pod, which can be linked to, just like the pages on a website. That gives people genuine control over where and how their data is deployed.
If it comes off, it would be a seismic change in the digital landscape.
"Some people are calling it Web 3.0," Sir Tim says.
And whereas previous attempts at what's known as re-decentralisation have foundered on public disinterest, this time Sir Tim feels the time is ripe.
"A big backlash [is coming] against the mistreatment of personal data, a realisation that people should control their data," he says.
"That's what I see, a revolution. Starting right now."