Tax authorities worldwide have benefited from their help and recovered billions: whistleblowers who pass on details of illegal banking practices. As far as the banks are concerned, these people are traitors, who violate the golden rule of bank secrecy.
Rudolf Elmer hit the international headlines as a whistleblower in 2008 after he turned over secret bank data to Wikileaks. His activities later led to charges of violating bank secrecy laws and a suspended fine. Made in Germany's Carmen Meyer caught up with him in Zurich.