Governments and internet firms are meeting to try and curb the spread of extremism online. Luca Collacciani of cybersecurity firm Akamai tells us how difficult it can be to police online material. Scott Carpenter of Jigsaw, a Google company which develops technology to tackle violence on the internet, explains how their service works. And Tel Aviv-based lawyer Nitsana Darshan-Leitner discusses legal action she's taking in the United States against social media companies on behalf of victims of terrorist attacks in Israel. Also in the programme, amidst an escalation of the trade war between China and the United States, the New York based business journalist Diane Brady assesses the prospects for a resolution to the dispute any time soon. Plus, as a painting by Claude Monet fetches a record $110m at auction, we look at the rise of online art sales with Sarah Ryan, whose website NewBloodArt sells pictures from emerging artists. (Picture: Social media apps on a smartphone. Picture credit: Getty Images.)