A massive leak of millions of documents has revealed that heads of state, criminals and celebrities conduct and sometimes conceal their business activities in tax havens. The leak exposes holdings in shadowy companies that are owned by 11 past and present heads of state, and reveals how partners of Russian President Vladimir Putin clandestinely transferred no less than $2 billion through banks and companies registered in tax shelters. For more information, visit: panamapapers.icij.org