MOSCOW—A new chill is spreading among Russian bloggers following the death of the journalist-owner of an opposition website.

While opposition viewpoints are rarely presented in Russian newspapers these days (and even less frequently on television), the Internet has remained a place where Russians of all ideological stripes are able to express themselves.

But following the mysterious death of Web journalist Magomed Yevloyev and the prosecution of disaffected bloggers, there are fears that authorities are trying to squeeze shut that remaining outlet for freewheeling debate.

The issue came sharply into focus with the August 31 killing of Yevloyev, the founder of a popular site called Ingushetia.org that reports on human rights abuses in the restive southern Russian region of Ingushetia.

After he landed at the airport in the Ingushetian town of Nazran, a police convoy picked him up. Less than an hour later, he was delivered to the hospital with a fatal bullet wound to his head. Prosecutors have suggested the shooting was an accident, perhaps the result of Yevloyev trying to grab an officer's gun, though his supporters say it was punishment for his muckraking site. "It was a premeditated murder," concludes Musa Pliyev, a lawyer for Ingushetia.org.

Russians have enjoyed unfettered freedom of speech on the Internet—the news site run by opposition head Garry Kasparov serves up stinging criticism of the state, while Russian bloggers of every political persuasion congregate on LiveJournal.

And there have been grand promises that the Internet will remain unrestricted, such as a June pronouncement by President Dmitry Medvedev that it should be protected from interference by authorities.

But according to activists, interference is already a fact.

Andrei Richter, head of Moscow's Media Law and Policy Institute, says there is no nationwide offensive such as China's Golden Shield Project, sometimes called the Great Firewall of China, which blocks access to a raft of news and blogging sites.

However, Russia's regional administrations are taking the initiative and charging bloggers who criticize the regime. They're "testing the waters, seeing which statutes work better in regulating the Internet," Richter says. "It's a very dangerous trend."

Russia's rulers ostensibly have little reason to worry about Net users. United Russia, the political party of Prime Minister Vladimir Putin and Medvedev, overwhelmingly dominates parliament and the country's political discourse, and Russians are happy with their increased affluence under Putin.

Still, that support could fade if, say, Russia's economy were to falter. "Now the government is realizing that the Internet is becoming political," says Clothilde le Coz, head of the Internet desk at Reporters Without Borders in Paris. "It's a means for people to gather and spread a message, for example against the government, and that's a problem."

Ingushetia.org, founded in 2001, documents abuses that rights organizations say are endemic in Ingushetia, in particular graft, and the abduction and killing of residents by security forces. Authorities often justify the killings in the name of a struggle with separatists and Islamists, although there has been a backlash. The Moscow Helsinki Group, a nongovernmental watchdog group, warned this month that Ingushetia is verging on a civil war.

Ingushetia.org frequently ranks as one of Russia's most-viewed sites. "We're the only site that talks about what is really going on in Ingushetia," says Roza Malsagova, its editor-in-chief, who oversees five editors and around 10 freelancers.

In recent years, Ingushetia.org's employees have come under increasing pressure.

The president of Ingushetia, Murat Zyazikov, has said the site aims to destabilize the region and accused it of "publishing materials of an extremist, anti-Russian bent."

Ingushetia.org's editors and lawyers have been subject to criminal charges and searches and are treated with deep suspicion; they communicate with each other using the Internet because they say their calls are monitored.

In April, a court ordered that the site, which formerly used the Russian domain ".ru" and was called Ingushetiya.ru, be shut down for inciting racial hatred. The site's lawyers said last week that a regional organization that manages domain names deleted its registration, though it immediately reappeared using the .org suffix.

And in August, Malsagova fled to Paris with her three teenage sons because she feared for her life.

Bloggers are another group that seems increasingly at risk; two who criticized police and the special services face charges of inciting hatred.

In the case of Dmitry Solovyov from the Kemerovo region, court documents cite five blog posts critical of law enforcers, though the posts often quote material from other sites or repeat anti-Kremlin sentiments that are hardly novel. None calls for violence against law enforcers.

"You can find worse statements than these all the time on the Internet. I don't understand why I've had these problems," says Solovyov, a graduate student.

One possible explanation: He's a member of an opposition movement, Oborona. Solovyov was reluctant to discuss the case as he said his calls are under surveillance.

Savva Terentyev, from Syktyvkar, in the Komi republic, received a one-year suspended sentence in July after posting a comment on a blog calling for Russian policemen to be set on fire. A day after receiving a recent inquiry from a reporter, Terentyev deleted his blog.

In Ingushetia, Yevloyev's death continues to reverberate. It sparked protests, and his relatives, steeped in the traditions of the Caucasus, declared "blood revenge" on the local president and police chief, meaning they intend to answer a killing with a killing.