From the BBC World Service… Despite an effort from Prime Minister Theresa May last night to reassure the British public and the country’s businesses about Brexit, firms are still worried about what happens next Friday when the clock strike midnight. We'll hear from businesses on both sides of the English channel about how they’re preparing in an increasingly uncertain environment. Then, Chinese president Xi Jinping is in Italy today – a country expected to become the first G-7 nation to officially endorse China's global Belt and Road Initiative.

The Fed decides to leave interest rates alone. Are courts equipped to handle matters of complex scientific questions? Plus, the top spot for happiest place on earth goes to — surprise — Scandinavia.

Today's show is sponsored by Panopto and WellFrame.

Marketplace Tech is taking a look this week at how people get radicalized online. They may start out as trolls making tasteless jokes, get sucked deeper into increasingly radical communities and maybe take the step to commit violence in the real world, like the Christchurch shooter in New Zealand. What can the biggest social media platforms in the world do to interrupt this process? Host Molly Wood talked with Dipayan Ghosh, who used to work on global privacy and public policy issues at Facebook.

What can the biggest social media platforms in the world do to radicalization online? Host Molly Wood talked with Dipayan Ghosh, who used to work on global privacy and public policy issues at Facebook. Now he's a researcher at the Harvard Kennedy School. He says, yes, it's hard for big platforms to minimize that content. But he says it's also not that hard.

It's no secret that nearly all of Facebook's revenue comes from advertising. But did you know Facebook is accused of allowing advertisers to discriminate against minorities, women and other protected groups? In some cases, civil rights groups say, Facebook made it possible for housing, job and credit advertisements to post to the feeds of white people or men exclusively — a violation of decades-old equal opportunity laws.