For the first time in recent memory, the United States is no longer among the world s premier spam distributors. Big changes in global spam distribution networks that followed takedowns of the Pushdo/Cutwail, Bredolab and Rustock botnets are the most likely cause. India, Indonesia, Brazil, Peru and Ukraine were the top producing countries in the Kaspersky survey, which ran from April through July. Nearly sixty percent of global spam is produced in only ten countries, increasingly located in Asia and Latin America.
Source: https://threatpost.com/spam-report-usa-no-longer-worlds-most-obnoxious-nation-091311/75650/