Why is that US Banks are lawndering billions dollars from drugs,Is US economy in agony?

The Guardian reported on Sunday that an extensive investigation by the IRS, DEA and FBI uncovered the porous money-laundering system. The feds found that cocaine smugglers successfully moved tens of billions of dollars in funds through Wachovia accounts using wire transfers, traveler's checks and cash shipments. The paper notes that the flow of cash through the bank began in 2004 -- coinciding with the rise of Mexico's menacing drug gangs and the increased violence on the U.S.-Mexico border.