A/HRC/17/27 76. In addition, while States are the primary duty-bearers of human rights, the Special Rapporteur underscores that corporations also have a responsibility to respect human rights, which means that they should act with due diligence to avoid infringing the rights of individuals. The Special Rapporteur thus recommends intermediaries to: only implement restrictions to these rights after judicial intervention; be transparent to the user involved about measures taken, and, where applicable, to the wider public; provide, if possible, forewarning to users before the implementation of restrictive measures; and minimize the impact of restrictions strictly to the content involved. Finally, there must be effective remedies for affected users, including the possibility of appeal through the procedures provided by the intermediary and by a competent judicial authority. 77. The Special Rapporteur commends the work undertaken by organizations and individuals to reveal the worldwide status of online impediments to the right to freedom of expression. He encourages intermediaries in particular to disclose details regarding content removal requests and accessibility of websites. Additionally, he recommends corporations to establish clear and unambiguous terms of service in line with international human rights norms and principles and to continuously review the impact of their services and technologies on the right to freedom of expression of their users, as well as on the potential pitfalls involved when they are misused. The Special Rapporteur believes that such transparency will help promote greater accountability and respect for human rights. 4. Disconnecting users from Internet access, including on the basis of intellectual property rights law 78. While blocking and filtering measures deny users access to specific content on the Internet, States have also taken measures to cut off access to the Internet entirely. The Special Rapporteur considers cutting off users from Internet access, regardless of the justification provided, including on the grounds of violating intellectual property rights law, to be disproportionate and thus a violation of article 19, paragraph 3, of the International Covenant on Civil and Political Rights. 79. The Special Rapporteur calls upon all States to ensure that Internet access is maintained at all times, including during times of political unrest. In particular, the Special Rapporteur urges States to repeal or amend existing intellectual copyright laws which permit users to be disconnected from Internet access, and to refrain from adopting such laws. 5. Cyber-attacks 80. The Special Rapporteur is deeply concerned that websites of human rights organizations, critical bloggers, and other individuals or organizations that disseminate information that is embarrassing to the State or the powerful have increasingly become targets of cyber-attacks. 81. When a cyber-attack can be attributed to the State, it clearly constitutes, inter alia, a violation of its obligation to respect the right to freedom of opinion and expression. Although determining the origin of cyber-attacks and the identity of the perpetrator is often technically difficult, it should be noted that States have an obligation to protect individuals against interference by third parties that undermines the enjoyment of the right to freedom of opinion and expression. This positive obligation to protect entails that States must take appropriate and effective measures to investigate actions taken by third parties, hold the persons responsible to account, and adopt measures to prevent such recurrence in the future. 21