Environmental Crime Scene

On my way to work this morning I passed an Environmental Crime Scene. Admittedly anyone who works in London is liable to pass one or two of these every day, mostly committed by the planners - the City skyline itself increasingly resembles one vast environmental crime scene. But this was in a sidestreet in (largely) unspoilt Kensington, where every prospect pleases. The Environmental Crime Scene was, in fact... a bag. It was a plastic bin-bag, apparently containing some kind of builders' waste, and it was propped up against a wall. Someone had bound said bag tightly from top to bottom and left to right with wide sticky tape bearing the legend 'ENVIRONMENTAL CRIME SCENE'. I have never seen such a thing before. Was it, I wonder, the work of some kind of activists - or the heavy hand of the municipal authorities? The latter, I suspect, determined to make their point.