A report by the Committee to Protect Journalists (CJP) has found that the number of online journalists being jailed is rising faster than any other group.
The report found that, of the 134 journalists imprisoned this year, 49 were online writers, second only to print journalists.
China, Cuba, Eritrea and Ethiopia were the states most likely to lock up journalists, but the US has two on the list.
These are Associated Press photographer Bilal Hussein, now held for eight months in Iraq without due process, and Al-Jazeera cameraman Sami al-Haj, jailed for five years and now held at Guantanamo Bay.
"We are at a crucial juncture in the fight for press freedom because authoritarian states have made the Internet a major front in their effort to control information," said CPJ executive director Joel Simon.
"China is challenging the notion that the internet is impossible to control or censor, and if it succeeds there will be far-ranging implications, not only for the medium but for press freedom all over the world."
China heads the table with 24 journalists jailed. They are usually held on charges of attacking the state and their arrest has sometimes been helped by co-operation with Western companies.
Other charges include property damage, regulatory violations, drug possession and "association with extremists".
Cuba is the second most likely to lock up members of the media, with 24 editorial staff in jail. The bulk of these were arrested in 2003 during a state crackdown on dissent.
Galván Gutiérrez, a journalist with independent news agency Havana Press, was tried under Article 91 of the penal code for acting against "the independence or the territorial integrity of the state".
In April 2003, Gutiérrez was sentenced to 26 years in prison which he was serving at the maximum security Agüica Prison in western Matanzas province.
Web journalists under increasing threat of jail
By Iain Thomson on Dec 11, 2006 9:47AM