Free speech group Freedom House said repressive laws, violent attacks on bloggers and government surveillance are among the biggest emerging threats to Internet freedom, CNN reported Friday.
Freedom house analyzed restriction of access, content censorship and violations of users' civil rights in 47 countries.
Iran, Cuba and China were the most repressive in terms of restricting Internet usage and freedoms, the group said.
Authorities in China conduct the most sophisticated censorship efforts, Freedom House said, because major Web portals and social networking sites, even though not state-owned, must obey with strict government censorship rules or risk being shut down.
Beijing's influence as an "incubator for sophisticated restrictions" has not gone unnoticed, the group said, with governments including Belarus, Uzbekistan and Iran following China's model for their own Internet crackdowns.
"The findings clearly show that threats to Internet freedom are becoming more diverse," Sanja Kelly, a project director at Freedom House, said.
"As authoritarian rulers see that blocked websites and high-profile arrests draw local and international condemnation, they are turning to murkier -- but no less dangerous -- methods for controlling online conversations."