The vast majority of fraud losses in the US result from white collar crime. Unfortunately, our criminal system does not inflict sufficiently harsh sentences to make white collar crime unattractive. Federal agents have also proven themselves unwilling, or incapable of recovering 100% of the ill-gotten gains in the past. Accordingly, I propose the creation of a punitive tax rate (i.e. 60%) applicable to all people convicted of white collar crimes. This would eliminate situations such as Michael Milken going to jail for 10 years, and then leaving with $500 million of fraudulent earnings still in the bank.
Note: This measure would probably also pay for the rest of the entire criminal justice system.