The BBC showed a news story a few months back of a speed camera van at work - the presence of the van - rather than making the road safer - was causing accidents as drivers panic braked on seeing the van.
Apparently it took the smug knobbers a couple of weeks to realise that their video exposed the counter-productive nature of the camera van - as we saw the ‘safety camera’ van inducing potentially fatal accidents in what would otherwise have been safe and trouble free 80/90 m.p.h. traffic. . .