President Obama and Treasury Secretary Tim Geithner announced on Monday a crackdown on offshore tax havens that could produce $210 billion in new tax revenue over the next decade.

In January, the Government Accountability Office issued a report that found that 83 of the 100 largest publicly traded U.S. corporations reported subsidiaries in countries listed as tax havens or "financial privacy jurisdictions."

Many of those corporations are beneficiaries of billions in taxpayer dollars under the Troubled Asset Relief Program. Morgan Stanley, for instance, boasts 273 subsidiaries in tax havens, with 158 in the Cayman Islands alone. Citigroup's got 427, with 90 in the Cayman Islands, and 59 of Bank of America's tax-haven subsidiaries are there as well.

The GAO found 18,857 businesses are registered at just one address in the Cayman Islands -- the "Ugland House." The report said that "Ugland House registered entities included investment funds, structured-finance vehicles, and entities associated with other corporate activities."