A/HRC/7/14 Page 18 under international law and resulted in human rights violations. In this context, the right to freedom of opinion and expression is particularly vulnerable to legislation that de facto legitimates limitations on the free circulation and expression of ideas and opinions, directly affecting the work of media professionals, human rights defenders, political groups and civil society more broadly. Journalists and media professionals have become common targets of unlawful attempts to restrict freedom of expression. 48. The restrictions brought about by counter-terrorism legislation on human rights in general, and the right to freedom of opinion and expression in particular, have taken many forms. A number of allegations were brought to the Special Rapporteur’s attention in this regard, including instances where Governments have passed laws that restrict individual liberties such as the right to privacy and to due process; arbitrary arrests and detentions conducted by the security apparatus; banning the publication of information that is, without justification, defined as being threatening to national security; forcing the disclosure of journalistic sources; censoring media outlets and journalists on the basis of an alleged proximity to terrorist or rebel groups. 49. The Special Rapporteur recalls that restrictions to the right to freedom of opinion and expression can only be imposed in rather exceptional circumstances. In this respect, the Special Rapporteur has referred in his previous reports, to General Comment No. 29 (CCPR/C/21/Rev.1/Add.11) of the Human Rights Committee, which establishes the conditions that must be met for a State to invoke article 4,paragraph 1, of the International Covenant on Civil and Political Rights (ICCPR), dealing with derogations to the rights enumerated thereto. Derogations established under article 4, paragraph 1, of the Covenant are exceptional in nature and can only be invoked when the situation within a State amounts to a public emergency which threatens the life of the nation and when the State party has officially declared a state of emergency. These restrictive measures imposed by the State must, inter alia, be strictly limited in time, provided for in a law, necessary for public safety or public order, serve a legitimate purpose, not impair the essence of the right, and conform to the principle of proportionality. The principles of legitimacy, necessity and proportionality must always be respected.