Technology Correspondent, BBC News website
Repressive regimes are taking full advantage of the net's ability to censor and stifle reform and debate, reveals a report.
Written by the Reporters Without Borders (RSF) pressure group the report highlights the ways governments threaten the freedom of the press.
The report has a section dedicated to the internet and the growing roster of nations censoring online life.
This censorship is practised on every continent on Earth, said the report.
Although the internet is changing the way the media works as blogs, chat forums and social networking sites turn passive consumers into active critics, it is not just citizens who are taking advantage of its technological power warned the report.
Julien Pain - who heads the internet freedom desk at the RSF and was one of the report's authors, noted: "Everyone's interested in the internet - especially dictators".
Mr Pain said the world's dictators have not remained powerless in the face of the explosion of online content. By contrast, many have been "efficient and inventive" in using the net to spy on citizens and censor debate.
In many nations, the net used to be the only uncensored outlet and the place people turned to for news they would never hear about through official channels.
However, noted the report, governments have woken up to the fact that the people they regard as dissidents are active online. Many are now moving to censor blogs and the last year has seen many committed bloggers jailed for what they said in their online journal.
For instance, in Iran Mojtaba Saminejad has been in jail since February 2005 for putting online material ruled offensive to Islam.
China was the nation that came in for most criticism for its efforts to monitor and censor the net. The RSF noted that net censorship in the country had undergone a significant shift in the last two years.
Originally, said the report, China was only interested in monitoring political dissidence on the net. Now its scrutiny covers general unrest in its population - ironically something that has grown because the net makes it easier for people to communicate.
China's success at censorship means it has effectively produced a "sanitised" version of the internet for its 130 million citizens that regularly go online.
The wide-ranging scrutiny also means that it is the biggest jailer of so-called cyber dissidents. RSF estimates that 62 people in China have been jailed for what they said online.
Net users have also been jailed in Egypt, Iran, Libya, the Maldives, Syria, Tunisia and Vietnam.
Where China has led, other nations are following and taking active steps to filter the net before it gets to their citizens. Zimbabwe is reportedly buying technology directly from China to beef up its censorship efforts.
Many other nations, including Burma, Cuba, Iran, Libya, Nepal, North Korea, Saudi Arabia, Syria, Turkmenistan, and Vietnam censor the net. Often this filtering involves stopping access to some types of sites, such as those showing pornography, but it can also involve blocking sites critical of governments or religions.
Some nations, such as Turkmenistan, have banned home net connections and restrict people to using net cafes which, said the RSF, were much easier to control. Burma has banned web e-mail systems such as Hotmail and Yahoo mail and every five minutes screen grabs are taken of what people are looking at in net cafes.
But criticism of the obstacles put before open net access was not limited to nations known for their repressive policies. The European Union was criticised too for its policy of leaving the decision on which sites to censor up to net service firms. This, said the RSF, created a "private system of justice" in which technicians take the place of a judge.
The 153-page report also criticised Western firms for selling technology to repressive regimes to help them monitor what people do online.
The report was produced to mark World Press Freedom Day.