Do Facebook, Google and Twitter have a conflict of interests when it comes to stopping Russia and others from manipulating public opinion and stoking conflict around the world? Presenter Ed Butler hears a range of voices raising concern about the existential threat that social media could pose to democracy, including Ukrainian government official Dmytro Shymkiv, journalist Berit Anderson, tech investor Roger McNamee and internet pioneer Larry Smarr. (Picture: Screenshot of Donald Trump tweet about Russia and Facebook)