A/HRC/RES/33/21 25. Urges all States to respect and protect the right to privacy, as set out in article 12 of the Universal Declaration of Human Rights, and article 17 of the International Covenant on Civil and Political Rights, including in the context of digital communication, and calls upon States, while countering terrorism and violent extremism conducive to terrorism, to review their procedures, practices and legislation regarding the surveillance of communications, their interception and the collection of personal data, including mass surveillance, interception and collection, with a view to upholding the right to privacy by ensuring the full and effective implementation of all their obligations under international human rights law, and urges them to take measures to ensure that any interference with the right to privacy is regulated by law, which must be publicly accessible, clear, precise, comprehensive and non-discriminatory, and that such interference is not arbitrary or unlawful, bearing in mind what is reasonable to the pursuance of legitimate aims; 26. Emphasizes the key importance of the full respect for the right to freedom of opinion and expression in efforts to fight terrorism and violent extremism conducive to terrorism, and also in countering the propaganda of terrorist and extremist groups, bearing in mind the provisions set out in the International Convention on Civil and Political Rights; 27. Urges States to ensure that any measure taken or means employed to counter terrorism and violent extremism conducive to terrorism, including the use of remotely piloted aircraft, complies with their obligations under international law, including international human rights law and international humanitarian law; 28. Also urges States, while undertaking counter-terrorism activities, to respect their international obligations regarding humanitarian actors and to recognize the key role played by humanitarian organizations in areas where terrorist groups are active; 29. Further urges States to undertake prompt, independent and impartial factfinding inquiries whenever there are plausible indications of breaches of their obligations under international law as a result of any measures taken or means employed to counter terrorism, and to ensure accountability for those responsible for violations that amount to crimes under national or international law; 30. Notes with concern measures that can undermine human rights and the rule of law, such as the detention of persons suspected of acts of terrorism in the absence of a legal basis for detention and due process guarantees, the unlawful deprivation of the right to life, and other fundamental freedoms, such as freedom of peaceful assembly and association, the deprivation of liberty that amounts to placing a detained person outside the protection of the law, the trial of suspects without fundamental judicial guarantees, the illegal deprivation of liberty and transfer of individuals suspected of terrorist activities, the return of suspects to countries without individual assessment of the risk of there being substantial grounds for believing that they would be in danger of subjection to torture, and limitations to effective scrutiny of counter-terrorism measures; 31. Stresses that all measures used in the fight against terrorism and violent extremism conducive to terrorism, including the profiling of individuals and the use of diplomatic assurances, memorandums of understanding and other transfer agreements or arrangements, must be in compliance with the obligations of States under international law, including international human rights law, international refugee law and international humanitarian law; 32. Urges States, while countering terrorism and violent extremism conducive to terrorism, to respect the rights to be equal before the courts and tribunals and to a fair trial, as provided for by international law, including international human rights law, such as article 14 of the International Covenant on Civil and Political Rights and, as applicable international humanitarian law and international refugee law; 4