Internet censorship is control or suppression of the publishing or accessing of information on the Internet. The legal issues are similar to offline censorship.

One difference is that national borders are more permeable online: residents of a country that bans certain information can find it on websites hosted outside the country. Conversely, attempts by one government to prevent its citizens from seeing certain material can have the effect of restricting foreigners, because the government may take action against Internet sites anywhere in the world, if they host objectionable material.

Barring total control on Internet-connected computers, such as in North Korea, total censorship of information on the Internet is very difficult (or impossible) to achieve due to the underlying distributed technology of the Internet. Pseudonymity and data havens (such as Freenet) allow unconditional free speech, as the technology guarantees that material cannot be removed and the author of any information is impossible to link to a physical identity or organization.

In November 2007, "Father of the Internet" Vint Cerf stated that he sees Government-led control of the Internet failing due to private ownership.

The following sections follow the OpenNet Initiative (ONI) categorization scheme: Pervasive, Substantial, Nominal, Indirect, Watchlist.

13 "Enemies of the Internet"

In 2006 the organization Reporters without Borders published a list of the 13 "enemies of the Internet":List of the 13 Internet enemies RSF, 2006 November

• flag: Belarus
• flag: Burma
• flag: China
• flag: Cuba
• flag: Egypt
• flag: Iran
• flag: North Korea
• flag: Saudi Arabia
• flag: Syria
• flag: Tunisia
• flag: Turkmenistan
• flag: Uzbekistan
• flag: Vietnam

Pervasive

While there is no universally agreed upon definition of what constitutes "pervasive censorship", organization Reporters without Borders (RSF) maintains an internet enemy list while the OpenNet Initiative categorizes some nations as practicing extreme levels of Internet censorship. Such nations often censor political content and may retaliate against citizens who violate the censorship with measures such as imprisonment.

Cuba

Cuba is on ONI's watchlist and on RSF's internet enemy list. Cuba has the lowest Latin America ratio of computers per inhabitant, and the lowest internet access ratio of all the Western hemisphere. Citizens have to use government controlled "access points", where their activity is monitored through IP blocking, keyword filtering and navigation history checking. According to the government, access to internet services by the Cuban population are limited due to high costs and the American embargo, but there are reports concerning the will of the government to control access to uncensored information both from and to the outer world. The Cuban government continues to imprison independent journalists for contributing reports through the Internet to web sites outside of Cuba