16 freedoms of others, an acceptable alternative must be provided that enables participants to effectively communicate their message within sight and sound of the target audience.20 The ODIHR Human Rights Handbook on Policing Assemblies states that most barriers will limit the movement of people and points out the danger that people may become trapped or crushed against them.21 Barriers can also become hazards if they are knocked over, as people might not be able to see them and might trip over them. The United Kingdom College of Policing has highlighted further risks in its list of considerations when using barriers, including that they can be used as weapons by hostile individuals, that they may trap participants in an assembly and police, and that their use may impinge upon the right to liberty and security of the person.22 Barbed wire, razor wire or any other spiked barrier or electrified wire, while deployed, creates an ongoing indiscriminate and uncontrollable risk of unintentional or unwarranted injury. Barriers of this type can disproportionately affect various groups, including children, persons with disabilities, pregnant women and persons of short stature. The use of such barriers, which have an additional offensive function that goes beyond the primary purpose of restricting access or movement, is disproportionate and unnecessary in a crowd-control setting and should be prohibited. Their use in such a setting does not meet a legitimate law enforcement objective that cannot be effectively accomplished with safer alternatives. This is confirmed by the United Nations Human Rights Guidance on Less-Lethal Weapons in Law Enforcement, which states that “Barbed wire, razor wire or other spiked barriers typically create an undue risk of injury to participants in an assembly. Where a barrier is needed, safer alternatives should be employed.”23 Vehicles that rapidly deploy barriers can be used to quickly encircle all or part of a crowd (see section on containment for further information on the associated health and human rights implications). Where moving vehicles are used as barriers and/or to corral a group of people, there is a particular risk of serious injury. 20 21 22 23 Ibid., p. 20. Ibid., p. 73. United Kingdom College of Policing, “Public Order: Tactical Options”, United Kingdom College of Policing website, <ht tps://w w w.app.college.police.uk/app-content/public-order/ planning-and-deployment/tactical-options/#barriers>. UN, Guidance on Less-Lethal Weapons in Law Enforcement, op. cit., note 7, para. 6.3.5.