In an investigative piece by Spencer Woodman for the International Consortium of Investigative Journalists (ICIJ), titled "Inside the IRS unit taking on America’s millionaires and billionaires," the challenges and strategic shifts of the U.S. Internal Revenue Service (IRS) in auditing the ultra-rich are laid bare. The article highlights the IRS's uphill battle against sophisticated tax avoidance strategies employed by millionaires and billionaires.