Paradoxically, while police officers are sworn to protect and preserve the expressive rights of civilians, they frequently are obliged to forego their own expressive rights as a condition of employment. In recent years, police have been challenging restrictive regulations as violations of their constitutional rights. Police expression cases tend to cluster around four issues: political participation, union activities, criticism of superiors, and personal grooming. Four cases set precedents in each of these areas. The precedent case regarding police free speech as applied to political participation is Paulos v. Breier (1974). In this case, the court let stand a 5 day suspension for using the influence of the police office for political reasons, noting Supreme Court decisions upholding the constitutionality of the Hatch Act limiting the political activity of Federal employees. The controlling precedent with regard to police and union affiliation is Ball v. City Council of the City of Coachella (1967). In this case, the court upheld the constitutional rights of police to belong to unions, and decided that engaging in union activities is not adequate justification for removal from office. In Muller v. Conslik (1970), a police officer's right to criticize his superiors was upheld, although the Court noted that police speech may be limited though not totally denied. In Greenwald v. Frank (1972), the Court found the interests of the State to outweigh personal freedom of grooming. Police free expression rights have developed from no rights to a balancing of state and individual interests. The paradox of the police who protect our freedoms but are forced to forego their own, however, remains.