O’REGAN J and SACHS J “[T]here is no absolute standard which can be laid down for determining reasonableness and necessity. Principles can be established, but the application of those principles to particular circumstances can only be done on a case-by-case basis. This is inherent in the requirement of proportionality, which calls for the balancing of different interests. In the balancing process the relevant considerations will include the nature of the right that is limited and its importance to an open and democratic society based on freedom and equality; the purpose for which the right is limited and the importance of that purpose to such a society; the extent of the limitation, its efficacy and, particularly where the limitation has to be necessary, whether the desired ends could reasonably be achieved through other means less damaging to the right in question.”49 We have concluded that section 20(1)(aA) limits both section 8 and section 13 of the interim Constitution. To determine whether either of these limitations are justifiable, we will look at each separately. In doing so, we shall consider, first, the nature and extent of the invasion of the right, second, the purpose of the limitation and, finally, whether the limitations pass the test of proportionality. For purposes of convenience, we deal first with the justification advanced in respect of the limitation on the right to privacy. The limitation of section 13 – the right to privacy 49 Id at para 104. 58