A/HRC/45/16 detention, the recourse to alternatives to detention is essential to ensure that detention meets the international standards, since detention in the migration context is permissible only as a measure of last resort.36 57. Over the past few years, the Working Group has observed new opportunities that the use of modern technologies, such as electronic monitoring devices and telephone and Internet reporting, offers to minimize the need for States to resort to traditional modes of deprivation of liberty, depending on the legal regime. 37 In principle, the use of digital technologies in providing alternatives to detention is a positive move. It limits the need for physical confinement of an individual in a closed environment, which usually represents a high cost to society and may lead to extended breaches of the rights of the individual concerned. The Working Group therefore welcomes the use of modern technologies to allow for alternatives to detention. 58. However, modern technologies must be used within the existing international human rights framework and the safeguards against their arbitrary application must be respected. The Working Group is particularly mindful of instances it has seen in its practice whereby the use of modern technologies has led to de facto discrimination. 38 For example, tools such as electronic tags can be expensive, which has led some countries to pass the associated cost on to the individual concerned.39 This in turn means that those from poorer backgrounds are not able to afford the associated cost and must therefore remain in detention facilities. This is an unacceptable situation and the Working Group recalls that the right to personal liberty belongs equally to everyone, irrespective of their economic or other status. Therefore, the application of modern technology to provide alternatives to detention must always be publicly funded and available to everyone on an equal basis. 40 59. Moreover, the decision for the application and use of such technology must be subject to judicial oversight to ensure that the use complies with the established legal framework, considering the combined principles of necessity and proportionality in fulfilling a legitimate objective, and is not otherwise arbitrary. The application and use of modern technology should never lead to disproportionate invasion of an individual’s privacy. 60. Noting the wide variety of approaches adopted by States worldwide, the Working Group calls upon the Human Rights Council to seek a thorough study on the use of modern technologies as alternatives to deprivation of liberty, in order to provide the requisite guidance for all States. IV. Conclusions 61. In 2019, the Working Group continued its work in addressing the large number of submissions received, including through its regular communications procedure. To that end, the adoption of opinions was set as a priority, resulting in the adoption of a total of 85 opinions, concerning 171 persons in 42 countries. 62. The Working Group notes with concern the response rate from States under its regular communications procedure and in the context of its follow-up procedure. In particular, States provided a timely response to the Working Group’s communications and requests for information in approximately 56 per cent of the cases in which the Working Group adopted an opinion in 2019. The Working Group received follow-up information from either the source or relevant Government in approximately 38 per cent of cases in 2019. 63. While the Working Group continues to respond to as many requests for its action as possible and to process cases in a timely and efficient manner in accordance with 36 37 38 39 40 Revised deliberation No. 5, paras. 14 and 16, and opinion No. 72/2017. See, for example, opinions No. 37/2018, paras. 24–25 and No. 84/2018. The relevance of electronic bracelets was also noted during the Working Group’s country visit to Greece. A/HRC/36/37/Add.2, para. 30, and A/HRC/39/45/Add.1, para. 83 (c). A/HRC/36/37/Add.2, paras. 36 and 53. A/HRC/39/45/Add.1, paras. 37–38. See also A/HRC/36/37/Add.2. 27