MOKGORO J Testing for Overbreadth as Part of the Limitations Analysis [48] Applicants’ overbreadth argument may present us with an opportunity to resolve the matter before us today without following United States and Canadian courts into the formidably difficult task of drawing lines between different kinds of sexually explicit speech, which is in any event primarily the task of the legislature. Applicants argue that the definition of proscribed material in the Act sweeps so widely that it unconstitutionally bans a great deal of incontestably constitutionally protected expression. 84 If that is so, there is no need for this Court to demarcate protected from unprotected sexually explicit speech, because whatever may be the legitimate scope of government regulation of sexually explicit material, the challenged legislation can be struck as being overbroad. [49] Overbreadth analysis is properly conducted in the course of application of the limitations clause. To determine whether a law is overbroad, a court must consider the means used, (that is, the law itself, properly interpreted), in relation to its constitutionally legitimate underlying objectives. If the impact of the law is not proportionate with such objectives, that law may be deemed overbroad. The Canadian case of Royal College of Dental Surgeons of Ontario v. Rocket,85 offers an example of this analysis in the free expression setting. The Canadian Supreme Court struck down as overbroad a ban on dentists’ advertising, using an analysis conducted under the Canadian Charter’s limitation clause. The Court held that while there was no doubt a legitimate government interest in preventing irresponsible and misleading advertising by dentists, the blanket ban challenged also struck at legitimate advertising, with the result that the test of 84 Applicants also make the separate, but connected, argument, that the said definition is unconstitutionally vague. For reasons that will become clear, it is not necessary to consider that head of Applicants’ argument. 85 [1990] 71 D.L.R. (4th) 68. 28