The Independent has given over its front page to highlight the plight of four bloggers currently serving prison sentences in places like China, Vietnam, Iran and Tunisia (See it here).

Amnesty International is also kicking off a campaign to defend persecuted bloggers and chatroom visitors.

Here's an excerpt from The Independent's story:

Amnesty International is launching a campaign on behalf of a whole new category of prisoners of conscience - internet bloggers and chatroom visitors arrested by repressive governments for expressing unwelcome views or disseminating sensitive information online.

In an appeal issued today, the human rights watchdog is urging webmasters around the world to stand up for their imprisoned fellow bloggers - in countries such as Iran, Tunisia, Vietnam and China - and denouncing major internet service providers, including Yahoo! and Microsoft, for providing foreign governments with the information they need to purge the web of dissenting voices.

The appeal comes on the eve of the inaugural meeting of the Internet Governance Forum, a UN-sponsored gathering in Athens to consider the future of online communication - including freedom of expression as well as security and intellectual property rights.

"People have been locked up just for expressing their views in an e-mail or on a website," said Steve Ballinger of Amnesty. "Sites and blogs have been shut down and firewalls built to prevent access to information. Companies have restricted internet searches to stop people accessing information that repressive governments don't want them to see.

"Countries and businesses have failed to respect, protect and promote the rights to freedom of expression, association and privacy, and the rights of human rights defenders."

Amnesty is issuing an urgent appeal on behalf of an Iranian blogger called Kianoosh Sanjari, who was arrested earlier this month after he provided reports on clashes between security forces and supporters of a Shia cleric called Ayatollah Boroujerdi. "He is being held incommunicado and [we fear] that he may be at risk of torture or ill-treatment," Amnesty said.

Here are the four bloggers:

CHINA

Published state secrets

Shi Tao was sentenced to 10 years in prison after "illegally providing state secrets to foreign entities".

His crime was to have e-mailed details of the Chinese government's plans to handle news coverage of the 15th anniversary of the Tiananmen Square massacre in 2004. Yahoo! provided crucial information in the case, linking the message and e-mail account with Shi 's computer. Reporters Without Borders accused Yahoo! of acting as a "police informant".

IRAN

Revealed arrest of dissidents

Kianoosh Sanjari was arrested on 7 October. The charges and his whereabouts are unknown. Mr Sanjari's blog gave information sympathetic to the Shia cleric Ayatollah Boroujerdi and his supporters. Up to the day of his arrest, he was providing details of the arrest of other dissidents and their detention at the notorious Evin prison.

Amnesty says he is being held incommunicado and is at risk of being tortured.

TUNISIA

Exposed state torture

Mohammed Abbou was sentenced in 2005 to four years in prison for assaulting a colleague at a lawyers' conference (a questionable charge) and for "having published information that would disturb public order".

Human rights activists believe Mr Abbou's real crime was to have posted a series of online articles denouncing the torture of political prisoners in Tunisia and comparing Tunisia's President, Zine el Abidine Ben Ali, to Israel's then prime minister Ariel Sharon.

VIETNAM

Denounced corruption by officials

Nguyen Vu Binh was sentenced to seven years in prison and three years' house arrest for "spying".

Mr Vu Binh wrote several online articles calling for greater political and economic freedoms, denouncing official corruption and calling for the establishment of a liberal democratic political party. He was called "reactionary" at his trial.

Reporters Without Borders says that Vietnam is second only to China in cracking down on internet freedom of expression.