US Airline United are at the centre of a social media storm after a video emerged of them dragging a man from a flight and apparently injuring him in the process.

The internet was quick to vent vitriol at the company on Twitter, Facebook, and elsewhere. So what kind of damage do these social media reactions cause companies? And can they control the fire of internet user anger?

Matt Cox asked Dan Appleby, Head of Client Services at social media marketing agency Drummond Central, and the North East city head of the Institute of Practitioners in Advertising, to find out more.