An examination of the influence of street stops on the legal socialization of young men showed an association between the number of police stops they see or experience and a diminished sense of police legitimacy. This association was not primarily a consequence of the number of stops or of the degree of police intrusion during those stops. Rather, the impact of involuntary contact with the police was mediated by evaluations of the fairness of police actions and judgments about whether the police were acting lawfully. Whether the police were viewed as exercising their authority fairly and lawfully shaped the impact of stops on respondents' general judgments about police legitimacy. Fairness and lawfulness judgments, in turn, were influenced by the number of stops and the degree of police intrusion during those stops. Similarly, judgments of justice and lawfulness shaped the estimated influence of judgments of the general character of police behavior in the community on general perceptions of police legitimacy. These results suggest that the widespread use of street stops undermined legitimacy. Lowered legitimacy had an influence on both law abidingness and the willingness to cooperate with legal authorities. The findings show that people were influenced by perceptions of police injustice/illegality.