The report said Libya and Venezuela were dropped from a list of countries "under surveillance" while India and Kazakhstan were added to it.
The countries listed as "enemies" of the Internet "combine often drastic content filtering with access restrictions, tracking of cyber-dissidents and online propaganda," the France-based organization said.
Bahrain and Belarus joined Myanmar, China, Cuba, Iran, North Korea, Saudi Arabia, Syria, Turkmenistan, Uzbekistan and Vietnam as countries "that restrict Internet freedom the most," the report said.
The report said countries "under surveillance" includes Australia, which still uses a content filtering system; Egypt, where new leaders resumed old practices and directly targeted outspoken bloggers; Eritrea, a police state that keeps its citizens away from the Internet; France, which has a "three-strikes" policy on illegal downloading and has introduced filtering by an internal security law; and Malaysia, which harasses bloggers in the run-up to general elections.
Russia also is on the "under surveillance" list because it has used cyber-attacks and arrested bloggers and netizens (Internet citizens) to prevent a real online political debate, the report said. Others under surveillance include South Korea, Sri Lanka, Thailand, Tunisia, Turkey, and the United Arab Emirates.
India was added to the "under surveillance" category because the country's officials have stepped up Internet surveillance and pressure on technical service providers ever since the 2008 bombings in Mumbai.
Kazakhstan has imposed cyber-censorship, despite its promises otherwise, by blocking news Web sites and imposing new, repressive Internet regulations.
While challenges remain in Libya, the overthrow of leader Moammar Gadhafi and his regime ended an era of censorship on the Internet, the report said in explaining the country's removal from the "under surveillance" category.
In Venezuela, the adoption last year of legislation that could potentially restrict Internet freedom hasn't yet shown any damaging effect, the report said. Reporters Without Borders said it would "remain vigilant as relations between the government and critical media are tense."
Reporters Without Borders said it would monitor online freedoms in countries such as Azerbaijan, Morocco, Tajikistan and Pakistan.
"At the time of writing, Pakistan has invited private-sector companies to bid for the creation of a national Internet filtering and blocking system," the report said. "Reporters Without Borders has asked the authorities to abandon this project, which would result in the creation of an Electronic Great Wall. If they go ahead, Pakistan could be added to the Enemies of the Internet in 2013."