A/HRC/28/28 metadata of communications for a period of up to 12 months. Concerns have been expressed that such blanket data retention may allow for the monitoring of communications of persons, even those outside of the State’s jurisdiction and those not suspected of any illegal activity.18 These developments all raise serious concerns about their compliance with the right of individuals to be protected by law against arbitrary or unlawful interference in their privacy. 26. States have adopted national legislation to implement targeted sanctions against individuals and organizations. While such measures can serve as an important tool for the prevention of terrorist acts, their serious potential repercussions on the human rights of those affected make efforts to ensure the right to due process of individuals affected essential.19 In some cases, such measures have given rise to the arbitrary banning of organizations based on ill-defined or vague legislation, sometimes with the objective of banning political dissent or otherwise peaceful means of expression. National legislation that fails to define “membership” or to require a link between the membership and the prohibited status or activity would be contrary to the principle of legality, in particular where such membership leads to targeted sanctions or criminal penalties, such as imprisonment. Any sanctions imposed by proscription should be a result of a clear indication, based on reasonable grounds, that the individual or entity has knowingly carried out, participated in or facilitated a terrorist act.20 27. The adoption of exceptional counter-terrorism legislation may be particularly problematic when it is not a stand-alone piece of legislation but rather an amendment to existing criminal laws and procedures. Experience has shown that counter-terrorism measures introduced in moments of crisis or extreme political stress and which are intended as short-term measures can readily become entrenched with the passage of time and invoked routinely by law enforcement authorities. 21 Much of the emergency legislation enacted by States in the wake of the terrorist attacks of 11 September 2001, for example, is still in force today. A sense of political urgency also may obstruct a proper a priori scrutiny of draft laws, and has led to the adoption of legislation that included imprecise definitions in counter-terrorism laws, opening the door for abuses in implementation. 28. I fully endorse the calls made in reports of the previous High Commissioner and underscore the importance of ensuring that counter-terrorism laws are consistent with human rights standards and comply with the principle of legality. Laws must be formulated with sufficient precision to enable an individual to regulate his or her conduct accordingly, and must be made accessible to the public. Laws must not confer unfettered discretion but rather provide sufficient guidance to those charged with their application to enable them to ascertain the sort of conduct that falls within their scope. 29. Regular review of the compliance of counter-terrorism laws and practices with human rights standards is critical in order to ensure that counter-terrorism measures are specific, necessary, effective and proportionate. Good practices highlighted by the High Commissioner in previous reports include a review of counter-terrorism legislation before 18 19 10 See legislation.gov.uk, Data Retention and Investigatory Powers Act 2014 and House of Commons, Oral Answers to Questions, 10 July 2014, Communications Data and Interception (www.publications.parliament.uk/pa/cm201415/cmhansrd/cm140710/debtext/1407100001.htm#14071054000003). See A/HRC/16/50 and A/HRC/22/26, and relevant reports of the Special Rapporteur on the promotion and protection of human rights while countering terrorism. 20 See for example A/HRC/16/50 and 51. 21 See for example International Commission of Jurists, Assessing Damage, Urging Action: Report of the Eminent Jurists Panel on Terrorism, Counter-terrorism and Human Rights (Geneva, ICJ, 2009).