Censorship of internet content can take many forms and ranges from governments blocking the dissemination of political opinion to blacklisting pornographic and pirate websites.

The OpenNet Initiative is a collaboration between three groups – the Citizen Lab at the University of Toronto's Munk school of global affairs, Harvard University's Berkman centre for internet & society and the SecDev Group in Ottawa – that investigates internet filtering around the world.

ONI principal investigator and Citizen Lab director Ronald Deibert says:

Originally and probably still to a large extent, pornography is both the most widely targeted content and also the one that's justified the most by countries. Most countries, if they're going to engage in internet censorship, start by talking about a broad category of inappropriate content. But what we've found over the last decade is the spectrum of content that's targeted for filtering has grown to include political content and security-related content, especially in authoritarian regimes. The scope and scale of content targeted for filtering has grown.

For each country, the ONI looks at the following four categories of filtering and gives each a rank ranging from "No evidence of filtering" to "Pervasive filtering":

• Political – content opposing the current government or its policies; can also relate to human rights, freedom of expression, minority rights or religious movements

• Social – content that might be perceived as offensive by the general population such as sexuality, gambling, illegal drugs, etc

• Conflict/security – Content related to armed conflicts, border disputes, militant groups and separatist movements

• Internet tools – Tools enabling users to communicate with others, circumvent filtering or that otherwise provide a service. Each country is then classified in terms of consistency – how consistently these topics are filtered across internet service providers – and transparency – how visible the process is by which sites are blocked and whether users are able to view what's on the blacklist.

According to the ONI data, Iran was the worst ranked, with "pervasive" filtering in the political, social and internet tools categories and "substantial" for conflict/security filtering. Tested in 2011, Iran's filtering was rated as being "highly" consistent and had "medium" transparency. Even the country's president isn't immune to the blacklist – it was reported in February this year that censors had blocked access to several news sites supporting Ahmadinejad ahead of the parliamentary elections in March. Worse yet, Iran has proposed a national internet, which would both increase the government's grip over individual connections but also restrict foreign users from accessing Iranian websites. Additionally, individuals are also required to provide personal details to even use a cybercafe.

After Iran was China, which had "pervasive" political and conflict/security filtering, along with "substantial" internet tools and social filtering. In addition to highly consistent filtering, China also had a lower transparency score than Iran. On April 12, Chinese users were cut off from all foreign websites, possibly due to a reconfiguration of the so-called "great firewall."

Meanwhile, authorities have shut down 42 websites since March this year. "The market for filtering technologies has grown worldwide; what started out as a market primarily oriented to corporate environments in the west has now become a major growing business for government," said Deibert.

Our research identified many corporations – mostly Silicon Valley corporations – that have provided products and services to regimes that have violated human rights. The market for these types of technologies that are used to implement control is growing more sophisticated

However, Deibert feels governments are moving away from widespread blacklists of websites to filter and towards what the ONI calls "next-generation filtering," which includes targeted surveillance and "just in time" filtering, or temporarily filtering content only when it's valuable – for instance, during an election. "We're seeing a trend away from traditional internet censorship and towards next-generation controls," he said. "The future is not in the great firewall but in the way countries like Iran have come to filter content."

Do you agree with the ONI assessment? Let us know in the comment field below. You can also download the data too direct from the ONI – what can you do with it? And what would you want to see it compared with?

Data summary

ONI ranking of each country for internet censorship Click heading to sort table. Download this data Country Political filtering Social filtering Internet tools filtering Conflict/security filtering United Arab Emirates substantial pervasive pervasive selective Afghanistan no evidence no evidence no evidence no evidence Armenia substantial selective selective selective Australia no evidence no evidence no evidence no evidence Azerbaijan selective selective no evidence no evidence Bangladesh no evidence no evidence no evidence no evidence Bahrain pervasive pervasive substantial selective Belarus selective selective selective selective Canada no evidence no evidence no evidence no evidence China pervasive substantial substantial pervasive Colombia no evidence selective no evidence no evidence Germany no evidence no evidence no evidence no evidence Denmark no evidence no evidence no evidence no evidence Algeria no evidence no evidence no evidence no evidence Egypt no evidence no evidence no evidence no evidence Ethiopia substantial selective selective selective Finland no evidence no evidence no evidence no evidence France no evidence no evidence no evidence no evidence United Kingdom no evidence no evidence no evidence no evidence Georgia selective no evidence no evidence selective Guatemala no evidence no evidence no evidence no evidence Croatia no evidence no evidence no evidence no evidence Hungary no evidence no evidence no evidence no evidence Indonesia selective substantial selective no evidence Israel no evidence no evidence no evidence no evidence India selective selective selective selective Iraq no evidence no evidence no evidence no evidence Iran pervasive pervasive pervasive substantial Italy no evidence selective no evidence no evidence Jordan selective no evidence no evidence no evidence Kyrgyzstan selective selective no evidence no evidence South Korea no evidence selective no evidence pervasive Kuwait selective pervasive pervasive selective Kazakhstan selective selective no evidence no evidence Laos no evidence no evidence no evidence no evidence Lebanon no evidence no evidence no evidence no evidence Sri Lanka no evidence no evidence no evidence no evidence Latvia no evidence no evidence no evidence no evidence Libya selective no evidence no evidence no evidence Morocco no evidence selective selective selective Moldova selective no evidence no evidence no evidence Burma (Myanmar) pervasive substantial substantial substantial Mauritania selective no evidence no evidence no evidence Mexico no evidence no evidence no evidence selective Malaysia no evidence no evidence no evidence no evidence Nigeria no evidence no evidence no evidence no evidence Norway no evidence no evidence no evidence no evidence Nepal no evidence no evidence no evidence no evidence Oman selective pervasive substantial no evidence Peru no evidence no evidence no evidence no evidence Philippines no evidence no evidence no evidence no evidence Pakistan selective selective selective substantial Gaza and the West Bank no evidence substantial no evidence no evidence Qatar selective pervasive pervasive selective Romania no evidence no evidence no evidence no evidence Russia selective selective no evidence no evidence Saudi Arabia substantial pervasive pervasive selective Sudan selective substantial substantial no evidence Sweden no evidence no evidence no evidence no evidence Singapore no evidence selective no evidence no evidence Syria pervasive selective pervasive selective Thailand selective selective selective no evidence Tajikistan selective no evidence no evidence no evidence Turkmenistan pervasive selective selective selective Tunisia no evidence selective selective no evidence Turkey selective selective selective no evidence Ukraine no evidence no evidence no evidence no evidence Uganda no evidence no evidence no evidence no evidence United States no evidence no evidence no evidence no evidence Uzbekistan pervasive selective selective selective Venezuela no evidence selective no evidence no evidence Vietnam pervasive selective substantial selective Yemen substantial pervasive pervasive selective Zimbabwe no evidence no evidence no evidence no evidence



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