- Hedge-fund billionaire Ken Griffin has sued the IRS and the Treasury Department over the "unlawful disclosure" of his tax information.- The leaked tax returns sparked an uproar in Washington, with the IRS inspector general and Justice Department investigating and Republicans frustrated by a lack of answers.Hedge-fund billionaire Ken Griffin has sued the IRS and the Treasury Department over the "unlawful disclosure" of his tax information, escalating the battle in Washington over leaked tax filings of super-wealthy people including Warren Buffett and Jeff Bezos.The claims stem from Griffin's inclusion in a ProPublica series in 2021 examining the taxes paid by top billionaires like Elon Musk and Carl Icahn, several of whom paid zero federal income taxes in certain years.Griffin was not listed as one of the billionaires who paid zero or low tax rates in any one year, and, in fact, the ProPublica tax information showed Griffin pays a higher effective tax rate than many top earners."