What is an example of something legal that you would be afraid of the IRS seeing? I can't imagine any scenario that most people (anywhere close to fifty percen

What is an example of something legal that you would be afraid of the IRS seeing? I can't imagine any scenario that most people (anywhere close to fifty percent of tax payers) would be willing to lose a significant portion to all of their refund check by needing to pay a tax preparer potentially thousands of dollars.