Almost 400 billionaires and millionaires from 24 countries have signed an open letter urging leaders to increase taxes on the world's wealthiest people. The letter released to coincide with the Davos economic summit has been signed by well known names including the actor Mark Ruffalo and the musician Brian Eno. They say that a "handful of global oligarchs with extreme wealth" have "cost everyone else everything else" and are driving society towards breakdown. #Tax #SuperRich #MarkRuffalo #BrianEno #C4News