I am already astonished by the role the big four audit firms have played in the crash of the Irish economy. But reading that PwC considers tax the most critical threat to business these days is rather mind boggling. PricewaterhouseCoopers is regularly contracted by the Central Bank, the Financial Regulator and the government to conduct evaluations of public institutions and businesses. The conclusions reached by PwC are used by these institutions for the creation of new policy. Do they really have our best interest at heart? That's of course a more rhetorical question.