MADLANGA J or grant interim relief, in the event of a suspension of the declaration of invalidity, and if we do, what its nature should be. Retrospectivity [137] If the declaration of invalidity has full retrospective effect, that will render unlawful everything done under RICA pursuant to the grant of all previous interception directions. These should not be undone. That scrambled egg is incapable of being unscrambled. Indeed, this Court has held that “[a]s a general rule . . . an order of invalidity should have no effect on cases which have been finalised prior to the date of the order of invalidity”.165 Suspension of declaration of invalidity [138] There is no question that interceptions of communications in terms of RICA serve an important government purpose. That much is clear from the several purposes for which interception directions may be issued, which have been discussed above. The country’s surveillance system would be seriously dislocated if a declaration of invalidity were not suspended. To refocus our minds on what would be affected, let me render a collection of the purposes for which interception directions may be issued. They may be issued if there are reasonable grounds to believe that: “a serious offence has been or is being or will probably be committed”;166 it is necessary to gather information concerning an actual threat to the public health or safety, national security or compelling national economic interests;167 it is necessary to gather information concerning a potential threat to the public health or safety or national security;168 the rendering of assistance to a foreign country in connection with or in the form of interception of communications is in accordance with an international mutual assistance agreement or is in the interests of South Africa’s international relations or 165 S v Bhulwana; S v Gwadiso [1995] ZACC 11; 1996 (1) SA 388 (CC); 1995 (12) BCLR 1579 (CC) at para 32. 166 Section 16(5)(a)(i). 167 Section 16(5)(a)(ii). 168 Section 16(5)(a)(iii). 72