The IRS has learned the Willie Sutton Principle: when it comes to revenues, go to where the money is.
New data from the IRS shows that tax filers with taxable incomes of $1 million or more were audited nearly 12 times more often than the population as a whole. About one in eight of them were examined in the fiscal year 2012, for a total of 41,000.
(Read more: Taxes Won't Stop Wealthy from Spending)
Those examinations have proven highly lucrative. The IRS found $4.8 billion in additional taxes from the audits. The average amount per return was $117,000.