One big reason for the Internet's success is its role as a universal standard, interoperable across the world. The data packets that leave your computer in Botswana are the same as those which arrive in Barbados. The same is increasingly true of modern mobile networks. Standards are converging: You can use your phone, access an app, or send a text, wherever you are.

CPJ's new analysis identifies Eritrea, North Korea, Syria, Iran as worst

CPJ Deputy Director Robert Mahoney counts down the 10 countries where the press is most tightly restricted. How do leaders in these nations silence the media? And which country is the worst of all? (4:03)

Read CPJ's report on the 10 Most Censored countries for more detail on how censorship works, and which countries were the runners-up.

China didn't make the cut for our 10 most censored countries. While the Chinese Communist Party's censorship apparatus is notorious, journalists and Internet users work hard to overcome the restrictions. Nations like Eritrea and North Korea lack that dynamism.

CPJ's Journalist Assistance Program supports journalists who cannot be helped by advocacy alone. In 2011, we assisted 171 journalists worldwide. Almost a fourth came from countries that made CPJ's Most Censored list. Eight journalists from Eritrea, five from Syria, six from Cuba, and a whopping 20 from Iran sought our help after being forced to leave their countries, having suffered the consequences of defying censorship at home.

Iran is the world's worst jailer of the press. Detentions rise in the Middle East and North Africa.

No independent press has operated in this Red Sea nation since a September 2001 government crackdown on dissent that led to the imprisonment of 11 leading journalists without charge or trial and the enforced closure of their publications. President Isaias Afewerki's administration consistently refused to account for the whereabouts, legal status, or health of the jailed journalists, or even confirm reports that some had died in custody. All of the journalists were held without access to their families or lawyers. The only media allowed to operate in the country were under the control of Information Minister Ali Abdu, who enforced rigid control of information and ideas through intimidation and imprisonment. Even state media journalists braved border guards' shoot-to-kill orders to escape the country. Government agents abroad harassed and intimidated media outlets established by exiled journalists. The government's egregious actions drew condemnation from the European Parliament in September 2011, the latest in a series of international censures.

Kassahun Yilma left Ethiopia quickly in December 2009. He didn't have time to save money for the journey, choose a place to go, arrange housing or a job. He left his wife, his mother, his house and all his friends behind. Yilma didn't know what lay ahead. He only knew that if he stayed, he risked becoming a victim of a government-waged campaign against Addis Neger, the newspaper where he worked as a reporter.  "I ran away just to save my life," says Yilma, "because I was in fear for it."

Stark regional differences are seen as jailings grow significantly in the Middle East and North Africa. Dozens of journalists are held without charge, many in secret prisons. A CPJ special report

The name Solomon Abera will forever be etched in the collective memory of Eritrea's press corps. On September 18, 2001, as the world focused its attention on the terrorist attacks on the United States, the government of Eritrea borrowed Abera's voice to sound the death knell, on state-controlled airwaves, of the Red Sea nation's independent press. Shortly after Abera read the announcement, the government rounded up leading independent newspaper editors and a dozen ruling-party dissidents calling for democratic reform -- all of whom have disappeared in custody.

Ten years to the day after being handed one of the most chilling news items he ever read on Dimtsi Hafash radio during his 14 years as a reporter, presenter, producer, and commentator, Abera reflected on the experience on our blog.

Today, we learned that Solomon Abera, who lived in exile in Germany after fleeing government censorship and intimidation in 2005, is no more.