MAJIEDT J [53] Then there are the cases concerning frivolous and vexatious litigation. There, self-evidently, the merits of the cases, both past and present, are germane in order to determine whether the court is being assailed by a further frivolous claim or something with arguable merits. In this category falls a case like Maphanga,54 on which much reliance was placed by the applicants. More about it later. Suffice to state for now that the passage relied upon reads: “It was firmly established in the South African common law, long before the advent of the Constitution, that the Supreme Court had the inherent power to regulate its own process and stop frivolous and vexatious proceedings before it. This power related solely to proceedings in the Supreme Court and not to proceedings in the inferior courts or other courts or tribunals. The following principles crystallised over the ages. It had to be shown that the respondent had ‘habitually and persistently instituted vexatious legal proceedings without reasonable grounds’. Legal proceedings were vexatious and an abuse of the process of court if they were obviously unsustainable as a certainty and not merely on a preponderance of probability. I must point out at this juncture that this definition applied to all litigation that amounted to an abuse of court process.”55 [54] The third class of case concerns criminal proceedings, public and private. The issue that arises in those cases is different. The enquiry is whether the prosecution is being brought in the public interest and not to pursue some private objective. That is a question of the legality of the proceedings and the permissible statutory purpose for which a prosecution may be instituted. A leading example is Zuma.56 In that case, the Supreme Court of Appeal had to consider an appeal against a decision of the High Court, in terms of which the decision on 27 December 2007 by the then Acting National Director of Public Prosecutions to indict former President Zuma on 54 Maphanga above n 15 and the cases cited there. 55 Id at para 25. 56 National Director of Public Prosecutions v Zuma [2009] ZASCA 1; 2009 (2) SA 277 (SCA). 25