In 2009, IRS commissioner Doug Shulman said in a speech that the IRS had formed a new group of auditors who were going to be directing their attention at a special group of taxpayers: the super rich. Dubbing them "global high wealth individuals," Shulman promised that his agency would be taking a hard look at people who had tens of millions of dollars worth of assets and income tied up in complicated financial dealings that often involved overseas banking and aggressive tax avoidance strategies.

http://motherjones.com/mojo/2012/04/super-rich-still-have-little-fear-irs