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Internet censorship

Legal control of the internet

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  • 6 chapters
Partial map of the Internet based on the January 15, 2005 data found on opte.org . Each line is drawn between two nodes, representing two IP addresses . The length of the lines are indicative of the d
The Opte Project · CC BY 2.5

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Through Internet, Jurisdiction and Age appropriateness

The extent of Internet censorship varies on a country-to-country basis. While some countries have moderate Internet censorship, other countries go as far as to limit the access of information such as news and suppress and silence discussion among citizens. Internet censorship also occurs in response to or in anticipation of events such as elections, protests, and riots. An example is the increased censorship due to the events of the Arab Spring. Other types of censorship include the use of copyrights, defamation, harassment, and various obscene material claims as a way to deliberately suppress content.

Support for and opposition to Internet censorship also varies. In a 2012 Internet Society survey, 71% of respondents agreed that "censorship should exist in some form on the Internet". In the same survey, 83% agreed that "access to the Internet should be considered a basic human right" and 86% agreed that "freedom of expression should be guaranteed on the Internet". According to GlobalWebIndex, over 400 million people use virtual private networks to circumvent censorship or for increased user privacy.

Age verification as a form of internet censorship to protect children is expanding to more jurisdictions, particularly since Australia passed its Online Safety Amendment on 27 November 2024, which came into force on 10 December 2025.

Overview

Many of the challenges associated with Internet censorship are similar to those for offline censorship of more traditional media such as newspapers, magazines, books, music, radio, television, and film. 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. Thus censors must work to prevent access to information even though they lack physical or legal control over the websites themselves. This in turn requires the use of technical censorship methods that are unique to the Internet, such as site blocking and content filtering.

Views about the feasibility and effectiveness of Internet censorship have evolved in parallel with the development of the Internet and censorship technologies:

  • A 1993 Time magazine article quotes computer scientist John Gilmore, one of the founders of the Electronic Frontier Foundation, as saying "The Net interprets censorship as damage and routes around it".
  • In November 2007, "Father of the Internet" Vint Cerf stated that he sees government control of the Internet failing because the Web is almost entirely privately owned.
  • A report of research conducted in 2007 and published in 2009 by the Berkman Klein Center for Internet & Society at Harvard University stated that: "We are confident that the [censorship circumvention] tool developers will for the most part keep ahead of the governments' blocking efforts", but also that "...we believe that less than two percent of all filtered Internet users use circumvention tools".
  • In contrast, a 2011 report by researchers at the Oxford Internet Institute published by UNESCO concludes "... the control of information on the Internet and Web is certainly feasible, and technological advances do not therefore guarantee greater freedom of speech".

Blocking and filtering can be based on relatively static blacklists or be determined more dynamically based on a real-time examination of the information being exchanged. Blacklists may be produced manually or automatically and are often not available to non-customers of the blocking software. Blocking or filtering can be done at a centralized national level, at a decentralized sub-national level, or at an institutional level, e.g., in libraries, universities or Internet cafés. Blocking and filtering may also vary within a country across different ISPs. Countries may filter sensitive content on an ongoing basis and/or introduce temporary filtering during key time periods such as elections. In some cases, the censoring authorities may surreptitiously block content to mislead the public into believing that censorship has not been applied. This is achieved by returning a fake "Not Found" error message when an attempt is made to access a blocked website.

Unless the censor has total control over all Internet-connected computers, such as in North Korea (who employs an intranet that only privileged citizens can access), or Cuba, total censorship of information is very difficult or impossible to achieve due to the underlying distributed technology of the Internet. Pseudonymity and data havens (such as Hyphanet) protect free speech using technologies that guarantee material cannot be removed and prevents the identification of authors. Technologically savvy users can often find ways to access blocked content. Nevertheless, blocking remains an effective means of limiting access to sensitive information for most users when censors, such as those in China, are able to devote significant resources to building and maintaining a comprehensive censorship system.

The term "splinternet" is sometimes used to describe the effects of national firewalls. The verb "rivercrab" colloquially refers to censorship of the Internet, particularly in Asia.

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