According to a recent audit report by the Treasury Inspector General, the IRS sent $7,219,518 in tax refunds in 2011 to what where–at least on paper–2,706 different aliens who were not authorized to work inside the United States. Unbelievably, all the funds were deposited into a single account.
In terms of strengthening fraud and theft detection, you would think that stopping this type of obvious abuse would be the “low-hanging fruit”.