A/HRC/16/51 abuses.43 Failure to restrict counter-terrorism laws and implementing measures to the countering of conduct which is truly terrorist in nature also pose the risk that, where such laws and measures restrict the enjoyment of rights and freedoms, they will offend the principles of necessity and proportionality that govern the permissibility of any restriction on human rights.44 27. In the absence of a universally agreed upon, comprehensive and concise definition of terrorism, counter-terrorism laws and policies must be limited to the countering of offences that correspond to the characteristics of conduct to be suppressed in the fight against international terrorism, as identified by the in Security Council in its resolution 1566 (2004), paragraph 3.45 While the international community is concerned with international terrorism, individual States affected by purely domestic forms of terrorism may also legitimately include in their terrorism definitions conduct that corresponds to all elements of a serious crime as defined by the national law, when combined with the other cumulative characteristics of resolution 1566 (2004).46 Properly defined, “terrorism” and associated offences are also accessible, formulated with precision, non-discriminatory and non-retroactive.47 Besides the characteristics identified in resolution 1566 (2004), definitions of terrorism often also refer to the motivation of the actors to advance a political, religious or ideological cause.48 While acts of terrorism are under no circumstances justifiable,49 and although this is not a conceptual requirement of a definition of terrorism, reference to these motivations can assist in further narrowing the scope of application of the definition of terrorism. 28. The Special Rapporteur takes the view that a definition of terrorism that goes beyond the following would be problematic from a human rights perspective, and therefore formulates the definition of terrorism below as a best practice in the fight against terrorism. Practice 7. Model definition of terrorism Terrorism means an action or attempted action where: 1. The action: (a) Constituted the intentional taking of hostages; or (b) Is intended to cause death or serious bodily injury to one or more members of the general population or segments of it; or (c) Involved lethal or serious physical violence against one or more members of the general population or segments of it; and 43 44 45 46 47 48 49 14 See E/CN.4/2006/98 (2005), para. 27, and E/CN.4/2006/78, para. 44. E/CN.4/2002/18, annex, para. 4 (b); E/CN.4/Sub.2/2005/39, para. 33; Council of Europe, Guidelines on Human Rights and the Fight against Terrorism, Guideline III(2); E/CN.4/1985/4, annex, paras. 10 and 51; general comment 29, op.cit., paras. 3-5. See also E/CN.4/2006/98, para. 39. A/HRC/10/3/Add.2, para. 6. See International Covenant on Civil and Political Rights , art. 15, General Assembly resolution 63/185, para. 18, and E/CN.4/2006/98, para. 49. See, for example, the questionnaire responses submitted by Australia, Canada, Malaysia and the United Kingdom. See, for example, the Declaration on Measures to Eliminate International Terrorism (General Assembly resolution 49/60), para. 1; and Security Council resolutions 1373 (2001), para. 3 (g), and 1566 (2004), para. 3.