Countries gagging for it...
Government censorship of internet content is widespread and on the rise.
Twenty-five out of 41 governments studied block or filter internet content, according to a survey carried out by OpenNet Initiative (ONI), which is made up of groups at Cambridge University, Harvard Law School, Oxford University and the University of Toronto.
Countries which filter internet content
According to the ONI study
♦ Saudi Arabia
♦ South Korea
♦ United Arab Emirates
This compares to just a few countries filtering content five years ago, said the researchers.
The governments are not just blocking websites but also services and applications such as Google Maps or Skype.
John Palfrey, professor of law at Harvard Law School, said in a statement: "Some regulation is to be expected as the medium matures but filtering and surveillance can seriously erode civil liberties and privacy and stifle global communications."
The top reasons for filtering are politics (blocking of opposition parties' sites); social norms (blocking activities such as pornography or gambling) and national security concerns (blocking radical groups' sites).
Countries take very different approaches. For instance China, Iran and Saudi Arabia filter content on a wide range of topics, while South Korea filters only one topic - North Korea - but does that extensively.
Iran is the one country listed as blocking across all three areas: politics, social issues and national security topics.
No evidence of filtering was found in 14 countries, including Afghanistan, Egypt, Iraq, Israel, West Bank and Gaza, Malaysia, Nepal, Venezuela and Zimbabwe, the researchers said.
The researchers chose to study countries whose state online surveillance practices were largely unknown. Because of this, a number of countries in Europe and North America were not included. It can be hard to compare these Western countries with those surveyed given that web control in the West tends to be done by the private rather than the public sector, the researchers said.
In future, the ONI hopes to expand the scope of the research to include internet cafés and mobile content - and expects to find more evidence of net censorship in later studies.