Money laundering was once considered a problem of "rogue" bankers. No longer. It is becoming increasingly clear that no one is immune to the siren song of easy profits. Earlier this month, major U.S. banks were slammed for their willingness to look the other way when dealing with ill-gotten funds. Public exposure and humiliation are integral parts of any strategy to fight money laundering. Penalties that hit the banks where it hurts — in their profits — will also help drive the message home: The flow of tainted funds must be stopped.

A defining feature of global mega-capitalism is the ease with which money moves around the world. But mechanisms that expedite international trade and investment also serve drug traffickers and organized-crime groups. No one knows how much money is being laundered, but estimates are in the hundreds of billions of dollars. Bank-secrecy laws facilitate the process; bankers who knowingly decline to ask questions are just as helpful. A combination of the two tops many criminals' wish lists.

But even those havens are dependent on the use of other banks to move money around. The worst offenders are usually small banks that are little more than shells. They use the services of other, global players to move the funds they launder. After all, there is little use for the massive amounts of funds these banks have to circulate in their tiny countries.