The organization Reporters Without Borders says North Korea, Turkmenistan, and Eritrea remain the most repressive countries for journalists. The annual ranking sees a worsening of press freedom in three major democracies - the United States, Japan and France.
The annual survey says North Korea remains the world's worst violator of free expression, ranking last in the list of 168 countries. The report's authors say Turkmenistan, at number 167, and Eritrea, at 166, have also clamped down further on press freedoms. They add that journalists in Cuba, Burma and China are risking their lives or their freedom to keep people informed.
The report puts northern European countries at the top of the index, as it did last year, finding no instances of censorship, violence, intimidation or reprisals against journalists in Finland, Ireland, Iceland and the Netherlands. All share first place in the ranking.
But Denmark dropped from a shared first-place last year to number 19 this year, because of threats against journalists who published controversial cartoons of the prophet Mohammed.
The United States fell nine places since last year's index and now ranks in 53rd place. The report was critical of restrictions on civil liberties under what it calls the "pretext" of national security.
The authors cite the jailing of San Francisco journalist Josh Wolf, who operates an internet weblog, for refusing to give the courts material from his video archive. They also cite the cases of Sami al-Haj, a Sudanese cameraman for the Arabic broadcaster Al-Jazeera who has been detained for five years at the U.S. military base at Guantanamo Bay, and Associated Press photographer Bilal Hussein, an Iraqi being held by U.S. authorities in Iraq. U.S. officials have called al-Haj an enemy combatant and say Hussein is suspected of having ties to insurgents, and say he is being held in accord with United Nations resolutions and the Geneva Conventions. Reporters Without Borders notes that neither has been charged with any crime.
France slipped five places in the survey to number 35, because of searches of the offices and homes of reporters, and attacks and threats on journalists who covered the violent demonstrations in French suburbs last November. Japan fell 14 places to 51st place, the report's authors citing the rise of Japanese nationalism and the country's exclusive system of press clubs as threats to media freedom.
The survey from Reporters Without Borders, a Paris-based group, is one several annual reports that address freedom of expression. The New York-based Committee to Protect Journalists issues its own investigative findings.
The committee's Abi Wright says journalists are under threat in many parts of the world. She adds that three are murdered every month.
"It is no surprise that Iraq came out at the deadliest country for journalists," she said. "It is actually the most dangerous conflict that we have every covered at the Committee to Protect Journalists in our 25-year history."
Other dangerous countries include Russia, where a prominent journalist, Anna Politkovskaya, was killed earlier this month.
Russia fell nine places to number 147 in the survey from Reporters Without Borders. The authors accuse Russian authorities of steadily dismantling the free media.
The report says changes of regime have brought welcome improvements in press freedom in Haiti, Togo and Mauritania. And two countries moved into the top 20 for the first time: 16th place Bolivia and 19th place Bosnia-Herzegovina.
Abi Wright of the Committee to Protect Journalists says there is a strong relationship between a free press and transparency in government and business, and so there are practical benefits from a free media. She says open societies are generally good places to invest in.
Reed Brody, a lawyer with Human Rights Watch, says press freedom is also a basic democratic right.
"It allows expression of grievances," he said. "It allows for the unveiling of corruption. It allows democratic participation. Without a free press, many of the other human rights that we take for granted and that we cherish would probably not exist."
Brody says despite some setbacks, press freedom is on the rise around the world. He says the growth of the Internet makes it easier for people to spread and share information and harder for governments to muzzle them. At the same time, he says that courageous reporting under totalitarian governments and in conflict-ridden regions remains very dangerous.