This week two companies have seen their reputations damaged, exacerbated in no small part by the wildfire speed of social media.

On Wednesday, the New York Times discovered fashion retailer H&M shredding unsold clothes from a Manhattan store rather than donating them to the homeless. At the same time, American media expressed outrage at a KFC TV commercial in Australia, which some felt was racist. (The commercial showed a white Australian cricket fan placating black West Indies fans with fried chicken).

Both brands found themselves caught out by the ferocity of the reaction. The stories were initially driven by Gawker and the Huffington Post, but it was when they were spread via Twitter and Facebook that the companies entered crisis mode.

KFC reacted by removing the offending ad, insisting the message had been misconstrued and re-asserting its multicultural credentials. Meanwhile, although its Facebook page was inundated with hostile messages, H&M provided no clear corporate response.

Like Trafigura and Jan Moir, H&M and KFC will have learnt a lesson about the viral damage that social media can cause, if left unchecked.