Audit!

The odds that your tax return will be Audited in a year are roughly
1 in 130 (0.77%)

Ben Franklin said that only two things are certain in life, "death and taxes". President Lincoln set up the IRS to make sure you could take care of both in one place.

(http://moneycentral.msn.com/content/Taxes/Avoidanaudit/P33948.asp)