Although the details are secret, American and Iraqi troops are on the offensive against Sunni Arab and terrorist gangs. Over a year of effort in building up an intelligence network among the population had paid off. Even in the Sunni Arab areas, many people are fed up with the lawlessness and violence created where the gangs operate. So information comes in about who is who and is doing what. This provides more, and higher quality, targets for raids. The ground units usually surround houses or compounds at night and arrest people, and seize weapons, bomb making equipment and documents, without a shot being fired. Some 30 areas have been identified as occupied and influenced by various gangs. The process of  clearing out these areas have apparently been underway for two weeks. Not a lot of publicity for this effort, as keeping the opposition guessing is a powerful weapon.