For more than a week, thousands of protesters conducted a campaign of civil disobedience in San Francisco's downtown area, blocking intersections, the entrances to government contractor companies, and generally causing confusion and frustration for people trying to get to work. The police department had been preparing for the protests for months and had decades of experience in handling downtown disturbances. The police were most concerned about the small percentage of hardcore anarchists who may have intended to engage in violence against property and the police. The police tactic was to keep the crowd moving while avoiding confrontation. The strategy worked, in that no less-lethal weapons had to be used against the protestors, and arrests were largely nonviolent; there were no serious injuries of protestors or police. The peaceful war demonstrations in Los Angeles were due largely to the peaceful disposition of the demonstrators, according to a police supervisor. The crowds responded well to the verbal instructions of the police during the demonstration. The larger task was to get the crowds to disperse after the demonstration concluded. In order to achieve this, the police did not use overwhelming force or confrontational tactics. The police simply asked the demonstrators to go home when the demonstration was over. The police were courteous and thanked the demonstrators for being orderly. The few people who did not comply with police instructions and requests (78 people) were quickly arrested without resistance. In New York City, where some anti-war protest crowds were estimated to be in excess of 100,000, police used advance information from permit request forms and their own formulas to estimate crowd size and the number of officers required to maintain order. Both the New York City and Los Angeles police departments have backup units prepared to take action should the crowds become seriously unruly. In Los Angeles this unit is called Metro, and in New York City it is the Special Operations Division. These units come into an unruly crowd with a strong show of force to intimidate and disperse the crowd. The key is to enter the scene with a clear display of superior resources and an announcement of the intent to make arrests if the crowd does not disperse. It is crucial that the police make correct assessments of the nature of the demonstration and the characteristics of participants, both through advanced knowledge and observation during the demonstration. The control and force used should be commensurate with the crowd's behavior. Cooperation between the police and the organizers of the demonstration prior to and during the demonstration is the key to minimizing problems.