One spring day, Bradley Birkenfeld boarded a flight out of Geneva, beginning a journey that would make him one of the greatest whistleblowers in financial history. The former banker with UBS provided information to U.S. authorities that would shatter Swiss banking secrecy and lead some 14,000 well-heeled Americans to fork over an astounding US$5 billion in unpaid taxes.

Abrasive and unsparing with criticism, Birkenfeld is not everyone’s model hero. He spent two and a-half years in a U.S. prison for helping a client evade taxes, yet collected a $104-million award for coming forward. Still, the enormity of his defining act is beyond dispute. So is the value of his perspective. He’s quick, for example, to note that many Canadians who banked with his former employer have never been called to account. “I’m bringing this news,” he says, “but nobody wants to talk about it.”