Facebook chief in global call to action
Mark Zuckerberg has revealed deep-seated concerns that the tide is turning against globalisation.
In an interview with the BBC, the Facebook founder said that fake news, polarised views and "filter bubbles" were damaging "common understanding".
He said people had been left behind by global growth, sparking demands to "withdraw" from the "connected world".
In a call to action, he said people must not "sit around and be upset", but act to build "social infrastructures".
"When I started Facebook, the mission of connecting the world was not controversial," he told me.
"It was as if it was a default assumption that people had; every year the world got more connected and that seems like the direction things were heading in.
"Now that vision is becoming more controversial."
He told the BBC: "There are people around the world that feel left behind by globalisation and the rapid changes that have happened, and there are movements as a result to withdraw from some of that global connection."
Mr Zuckerberg's interview comes alongside the publication of a 5,500-word letter he has written about the future of Facebook and the global economy.
In it Mr Zuckerberg quotes Abraham Lincoln who spoke of acting "in concert", and talks about "spiritual needs", civic engagement and says that many people have "lost hope for the future".
"For a couple of decades, may be longer, people have really sold this idea that as the world comes together everything is going to get better," he said.
"I think the reality is that over the long term that will be true, and there are pieces of infrastructure that we can build to make sure that a global community works for everyone.
"But I do think there are some ways in which this idea of globalisation didn't take into account some of the challenges it was going to create for people, and now I think some of what you see is a reaction to that.
"If people are asking the question, is the direction for humanity to come together more or not? I think that answer is clearly yes.
"But we have to make sure the global community works for everyone. It is not just automatically going to happen.
"All these different kinds of institutions, whether they are governments, or non-profits, or companies, need to do their part in building this infrastructure to empower people so that it creates opportunities for everyone, not just some people.
"If you are upset about the direction things are going in, I hope you don't just sit around and be upset, but you feel urgent about building the long term infrastructure that needs to get built," Mr Zuckerberg said.
I asked him whether he felt President Trump agreed with his view that "bringing people together" and "connecting the world" would lead to greater progress.
Mr Zuckerberg did not, famously, attend the round-table of technology leaders hosted by the new president.
"I don't think I am going to speak to that directly," he answered carefully. "You can talk to him, you can look at what he has said to get a sense of that.
"The thing that I will say is that a lot of folks will look at this through the lens of one or two events, and I really do think this is a broader trend.
"I have been talking about this for a long time, since before recent elections both across Europe and Asia and the US.
"A lot of today's biggest opportunities will come from bringing people together - whether that is spreading prosperity or freedom, or accelerating science, or promoting peace and understanding."