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.

The extent of Internet censorship varies on a country-to-country basis.

The blocking of Daily Motion in early 2007 by Tunisian authorities was, according to the Open Net Initiative, due to Secure Computing wrongly categorizing Daily Motion as pornography for its Smart Filter filtering software.

It was initially thought that Tunisia had blocked Daily Motion due to satirical videos about human rights violations in Tunisia, but after Secure Computing corrected the mistake access to Daily Motion was gradually restored in Tunisia.

According to Global Web Index, over 400 million people use virtual private networks to circumvent censorship or for increased level of privacy.

Many of the changes 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.

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".Other areas of censorship include copyrights, defamation, harassment, and obscene material.Support for and opposition to Internet censorship also varies.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.On 12 March 2013 in a Special report on Internet Surveillance, Reporters Without Borders named five "Corporate Enemies of the Internet": Amesys (France), Blue Coat Systems (U.