Internet censorship is the control or suppression of what can be accessed, published, or viewed on the Internet enacted by regulators, or on their own initiative.
Individuals and organizations may engage in self-censorship for moral, religious, or business reasons, to conform to societal norms, due to intimidation, or out of fear of legal or other consequences.
In a 2012 Internet Society survey 71% of respondents agreed that "censorship should exist in some form on the Internet".
Pseudonymity and data havens (such as Freenet) 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.
Other areas of censorship include copyrights, defamation, harassment, and obscene material.
Support for and opposition to Internet censorship also varies.
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.
Writing in 2009 Ronald Deibert, professor of political science at the University of Toronto and co-founder and one of the principal investigators of the Open Net Initiative, and, writing in 2011, Evgeny Morzov, a visiting scholar at Stanford University and an Op-Ed contributor to the New York Times, explain that companies in the United States, Finland, France, Germany, Britain, Canada, and South Africa are in part responsible for the increasing sophistication of online content filtering worldwide.
While the off-the-shelf filtering software sold by Internet security companies are primarily marketed to businesses and individuals seeking to protect themselves and their employees and families, they are also used by governments to block what they consider sensitive content.
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.
According to Global Web Index, over 400 million people use virtual private networks to circumvent censorship or for increased level of privacy.