Advertising Duffy or Diet Coke?

I stumbled across this advert when browsing around the Guardian website. It bought two interesting points, 1) it seems to be more of an advert for Duffy rather than Diet Coke! 2) This is the interesting part, according to reports, Police in the area had to stop a number of "copy cats" who also cycled through supermarkets in tribute to Duffy! Perhaps not the response the advertising people of Diet Coke were looking for?!