Hello and welcome to the Intelligence on Economist Radio. I'm your host, Jason Palmer.

Every weekday we provide a fresh perspective on the events shaping your world.

While gun deaths have dropped dramatically in big American cities such as New York and

Los Angeles, the murder rate in Chicago has remained stubbornly high, spiking in 2016.

A new program is working to reduce the violence by drawing lessons from West African research.

And once upon a time in lands far, far away, there lived kings and queens. Lots of them.

These days there are far fewer monarchies in the world, but stories like this weekend's coronation

of Thailand's new king are big news. What made so many monarchies disappear and what's to be

learned from those there left.

But first, in 2005 when YouTube was new, there wasn't much to see. Mostly home videos,

pratfalls and a few intrepid video bloggers. Since then, it's become the free television

service for much of the world. Now it's owned by Google and more than two billion people visit

this site at least once a month. The volume on offer of entertainment, education, information,

and well-wasted time is hard to fathom. It would take 100,000 years to watch all of it.

But with YouTube's incredible growth, I've come the challenges of moderating the dark side of

its content. Susan would just get the first message about the New Zealand massacre, not long after

began around 8 p.m. at her home in northern California. Gaudi-Ebstine is our media editor.

So the assaults on two mosques in Christchurch had begun maybe 15, 20 minutes earlier. The shooter

had livestreamed the killings on Facebook and footage from Facebook was being shared on YouTube

as the killer had clearly hoped. Ms. Wajiski is the CEO of YouTube, so she checked in with her team.

She had an incident commander that was already at work at the time, content reviewers around the

world. The world's largest video platform was mobilized to cleanse the self of this

...