Olson's report found that for the 2009 program, launched after a landmark crackdown on Swiss bank giant UBS AG for enabling wealthy Americans to dodge taxes through hidden private accounts, the average taxpayer ended up paying penalties averaging nearly four times, or 386%, of the basic tax owed.

Less wealthy taxpayers fared even worse. Olson found that the bottom 10% of those who entered the 2009 program, as measured by an average account balance of $44,885, got hit with penalties equal to nearly six times the amount of tax owed. Taxpayers wending their way through the program without legal representation got hosed even more, paying penalties of eight times. By contrast, the largest tax dodgers got socked with penalties equal to three times their unreported tax bills -- perhaps a sign of good lawyering affordable by the wealthy.

"The penalties are extraordinarily high as compared with most other penalties the IRS administers," Olson's report says.