In a report published Wednesday, ONI said human rights organizations and free speech advocacy groups many bloggers in the Middle East and North Africa have been jailed.
The report quoted the Committee To Protect Journalists, which listed the 10 worst countries in which to be a blogger, including Egypt, Syria, Tunisia and Saudi Arabia.
In April, the International Federation of Journalists called for a radical change to media laws in the Middle East, which it said jails journalists who allegedly undermine the reputation of the state, president, monarch or religion, the report said.
ONI said it based its evaluations on the scope and content of filtering sites in each country based on political, social, security and Internet-related categories.
The results of the study indicated the majority of Middle Eastern and North African countries heavily filter social content, including Iran, Bahrain, Oman, Qatar, Saudi Arabia, Tunisia and Yemen.
Bahrain, Iran, Syria and Tunisia were listed as the countries that practice the strictest political filtering, the report said.
ONI said its aim is to investigate, expose and analyzes Internet filtering and surveillance practices in a credible non-partisan fashion. The initiative is the collaboration of four academic institutions in Canada, the United States and Britain.