A/HRC/17/27 blocked, as witnessed in the context of recent protests across the Middle East and North African region. In Egypt, users were disconnected entirely from Internet access. 31. States’ use of blocking or filtering technologies is frequently in violation of their obligation to guarantee the right to freedom of expression, as the criteria mentioned under chapter III are not met. Firstly, the specific conditions that justify blocking are not established in law, or are provided by law but in an overly broad and vague manner, which risks content being blocked arbitrarily and excessively. Secondly, blocking is not justified to pursue aims which are listed under article 19, paragraph 3, of the International Covenant on Civil and Political Rights, and blocking lists are generally kept secret, which makes it difficult to assess whether access to content is being restricted for a legitimate purpose. Thirdly, even where justification is provided, blocking measures constitute an unnecessary or disproportionate means to achieve the purported aim, as they are often not sufficiently targeted and render a wide range of content inaccessible beyond that which has been deemed illegal. Lastly, content is frequently blocked without the intervention of or possibility for review by a judicial or independent body. 32. The Special Rapporteur notes that child pornography is one clear exception where blocking measures can be justified, provided that the national law is sufficiently precise and there are effective safeguards against abuse or misuse, including oversight and review by an independent and impartial tribunal or regulatory body. However, he is also concerned that States frequently rely heavily on blocking measures, rather than focusing their efforts on prosecuting those responsible for the production and dissemination of child pornography. Additionally, as child pornography is often a by-product of trafficking and prostitution of children, the Special Rapporteur urges States to take holistic measures to combat the root problems that give rise to child pornography. B. Criminalization of legitimate expression 33. The types of action taken by States to limit the dissemination of content online not only include measures to prevent information from reaching the end-user, but also direct targeting of those who seek, receive and impart politically sensitive information via the Internet. Physically silencing criticism or dissent through arbitrary arrests and detention, enforced disappearance, harassment and intimidation is an old phenomenon, and also applies to Internet users. This issue has been explored in the Special Rapporteur’s report to the General Assembly under the section on “protection of citizen journalists” (A/65/284). Such actions are often aimed not only to silence legitimate expression, but also to intimidate a population to push its members towards self-censorship. 34. The Special Rapporteur remains concerned that legitimate online expression is being criminalized in contravention of States’ international human rights obligations, whether it is through the application of existing criminal laws to online expression, or through the creation of new laws specifically designed to criminalize expression on the Internet. Such laws are often justified on the basis of protecting an individual’s reputation, national security or countering terrorism, but in practice are used to censor content that the Government and other powerful entities do not like or agree with. 35. One clear example of criminalizing legitimate expression is the imprisonment of bloggers around the world. According to Reporters without Borders, in 2010, 109 bloggers were in prison on charges related to the content of their online expression.16 Seventy-two 16 10 Available from: http://en.rsf.org/press-freedom-barometer-journalists-killed.html?annee=2010.