It is time the authorities took action against members of Citizens' Radio for operating an unregistered radio station. If the law is to mean what it says, the activists should be prosecuted. Legal action would also give the courts a chance to determine whether, as the radio station claims, the right to free speech is being denied by the existing regulatory scheme. For over a year, Citizens' Radio has openly defied the law by intermittently hijacking radio frequencies assigned to Metro Radio to broadcast illegally. The Office of the Telecommunications Authority (Ofta) has seized its equipment several times, but no arrest or prosecution has been made. Ofta appears to have taken care not to arrest the station's key backers. Last month, it raided premises used as a makeshift radio station, but did so when Tsang Kin-shing, a former legislator and mastermind of Citizens' Radio, was out of town. The 'goodwill' displayed by Ofta has not been appreciated, however, and the illegal station went on air again last night. Mr Tsang and his colleagues' deliberate moves to defy the law are aimed at forcing the courts to consider their argument that our broadcasting regime does not provide for sufficient diversity. The issue is a serious one. Rather than continuing to dodge it, Ofta should face up to the fact that it is dealing with a band of diehard activists who do not easily give up their ideals. The best way of dealing with their argument is to arrest them so the courts will have the opportunity to make a determination. Freedom of speech is not an absolute right and there are occasions where appropriate restrictions are justified. In the case of broadcasting, the relevant radio frequencies are a scarce asset. The law thus provides that they be parcelled out to specified operators, who must operate according to rules aimed at ensuring they act in accordance with the public interest. In time, the scarcity argument may no longer apply, as the introduction of digital technology will allow the existing spectrum to accommodate many more channels. As things stand, however, the existing allocation of frequencies should be respected as it is founded on proper legal and technical considerations. Citizens' Radio contends that existing operators have scuttled free speech by barring certain outspoken commentators from the airwaves. Instead of lobbying for a change of the relevant legislation, however, it started the illegal broadcasts. Last September it also submitted a formal application to operate a licensed public station. An official response from Ofta has not yet been given and is long overdue. It has, however, maintained that most airwaves are already occupied. Unless action is taken, Citizens' Radio can be expected to continue to flout the law. While diversity, so far as is technically possible, is to be welcomed on the airwaves, this farcical situation should be brought to an end.