The pranksters who last year duped BBC World into broadcasting what it thought was Dow Chemical's offer of a compensation fund for victims of the Bhopal disaster in 1984 have struck again. The Yesmen, anti-corporate activists, posed as representatives of Dow at a banking conference in London last week.

They presented the Acceptable Risk Calculator, which purported to "weigh profits against costs in human life or health, thereby involving the public in the decision-making process about whom to put at risk and where to locate risk globally". The pranksters - assisted by "mascot" Gilda, a life-sized golden skeleton - claim that many bankers signed up for licences for the calculator. The conference organisers on Wednesday confirmed the Yesmen's account of events. www.dowethics.com/risk