translate English to French: Many people claimed it was impossible because of the existence of tax havens, but it had been proved that there was a system of compensation between banks which made it possible to monitor all capital movements.
Beaucoup prétendent que c’est impossible en raison de l’existence des paradis fiscaux, mais il a été prouvé qu’il existe entre les banques un système de compensation qui permet de contrôler tous les mouvements de capitaux.