China is notorious for the tight reins it keeps on bloggers from that country. That censorship is so sharp that Chinese bloggers gained worldwide recognition last month when many were able to blog freely about the devastating earthquakes there because Beijing censors were too overwhelmed by the disaster to monitor blog posts.

The fastest growing category for arrests of citizen bloggers was for exposing corruption or human rights violations, he added. "In most democracies a whistle blower can get in touch with a journalist easily," he noted. "In a lot of the tougher authoritarian regimes, there is no tradition of or respect for whistle blowing. Blogs are taking on that whistleblowing function."

While Iran, Egypt and China were the most likely to arrest citizen bloggers during the five years studied, Howard said emerging democracies like Malaysia, Singapore and Thailand also posted some arrests, which surprised the researchers. "They are not familiar with how to deal with citizens who speak out," he noted.

While the research did not show that arrests stifled the free speech of bloggers, it did show that such arrests are driving citizens to new media like YouTube, Facebook and MySpace to comment on the arrests. "When the regimes crack down on bloggers, there is a spike in YouTube [postings about the blogger arrests]," he noted. "When word spreads that the government is cracking down on bloggers, people will turn to other ways of expressing themselves politically."

Howard noted that his research found 344 arrests logged online by the Committee to Protect Bloggers, but that the information did not detail of all the those arrested were bloggers or other activists. As a result, those arrests were not recorded in the study.

Researchers only included bloggers who were arrested for using electronic media, which included online blogs, videos and text messages, to discuss or record political issues or events, according to the study. The news reports and other online published details of the arrests cited various reasons for the arrests including refusal to give information to the government and violating rules unrelated to state security, the report said.