Charismatic race car driver (and 2007 Dancing With the Stars winner) Helio Castroneves is happier than usual to be competing in the Indy 500 this weekend. He was acquitted of 6 counts of federal tax evasion only three weeks ago.

For most kinds of crime, "ignorance of the law is no excuse." But the U.S. Supreme Court held in Cheek v. United States that the tax code was so darn complicated that a good faith belief that one was correctly interpreting the law was a defense to charges of tax evasion. We may not all have corporations in Panama, but we can surely relate to the task of puzzling over a deduction.