Several online journalists have been arrested recently.
The recent arrest of several bloggers, online journalists, and Internet technicians in Iran has raised fears that the country's old guard is determined to muzzle dissent in cyberspace.
The Internet has become a refuge for liberal journalists since the hard-line judiciary closed scores of reformist publications over the past four years. The Web log, or blog, format - a cross between a diary and public commentary - has allowed dissident writers to reach a mass audience with less of the expense and oversight of print media.
Government efforts to curtail this new forum are seen in Tehran as linked to the ascendancy of hard-liners who wrested control of parliament from reformers earlier this year after elections that many moderates were banned from contesting.
"They [hard-liners] see all these websites, including blogs, as newspapers they haven't been able to crack down on yet," says Hossein Derakhshan, a Canada-based Iranian blogger.
New laws covering "cyber crimes" were announced last week by the head of the judiciary, Ayatollah Mahmoud Shahrudi.
"Anyone who disseminates information aimed at disturbing the public mind through computer systems or telecommunications ... would be punished in accordance with the crime of disseminating lies," he declared.
At the same time, a judiciary spokesman said that people running unauthorized sites would soon be tried on charges including "acting against national security, disturbing the public mind, and insulting sanctities."
The government had originally focused on blocking pornographic sites. Reformist President Mohammad Khatami, told a UN digital summit in Geneva last year that his country blocked access only to "pornographic and immoral" sites that were not compatible with Islam. But, he insisted: "We are not censoring criticism. Criticism is OK."
Prominent bloggers include a key Khatami ally and presidential adviser, Mohammad Ali Abtahi, who resigned as vice president for legal and parliamentary affairs earlier this month, saying he could not work with the Parliament. His enemies saw him as the voice of Khatami's attempt to introduce greater democracy and freedom. Mr. Abtahi's lively blog covers subjects from soccer to freedom of speech. When two reformist papers were shut in July, he wrote in his blog that the "voice of the majority will not be heard any more."