In the meantime the strikers have to see to it that the employer does not find someone else with whom he can cooperate in order to eliminate his dependence upon them. Hence they picket the plant, in an attempt to persuade others not to work there. If persuasion is not effective, they may resort to mass picketing, which amounts to a threat of violence against the persons who would attempt to take over their jobs. On occasion the threat to their jobs becomes so great that in order to defend them they will resort to violence against the strikebreaker. At this point, the public, which is apt to be somewhat sympathetic toward their demands for fair wages or better working conditions, turns against them and supports the employer, greatly adding to his moral standing and weakening that of the strikers, until the strikers, feeling that the forces against them are too great, are apt to give way. The employer will find the same negative reaction among the public if he tries to use violence in order to break the strike. Hence, if he does decide to use violence, he tries to make it appear that the strikers are responsible, or tries to induce them to use it first. It is to their advantage not to use it, even when it is used against them. Labor leaders in general understand this principle and try to avoid violence at all costs. They do so not on the basis of principle, but on the basis of expediency.[39] In the great wave of enthusiastic organization of labor that swept over the United States in 1936 and 1937, American labor copied a variant of the strike, which had been used earlier in Hungary and in France.[40] Instead of leaving the property of the employer and trying to prevent others from entering it to take their places, workers remained on a "sit down strike" within the plants, so that the employer would have been forced to use violence to remove them in order to operate the factory. These strikes were based in part upon the theory that the worker had a property right to his job, just as the employer did to his capital equipment. Such strikes were for a time more successful than the older variety, because strike-breaking was virtually impossible. However, it was not long before public opinion forced the abandonment of the technique. It was revolutionary in character, since it threatened the old concept of private property. The fear of small property holders that their own possessions would be jeopardized by the success of such a movement, made them support the owners of the plants against the strikers, who were then forced to give way. In this case the public's fear of revolutionary change was greater than their dislike of violence, so they even supported the use of physical force by the employers and the police authorities to remove the strikers from the plants. The very effectiveness of the method which labor was employing brought about its defeat, because the public was not yet persuaded to accept the new