Internet the Internet or internet

Censorship
Main articles: Internet censorship and Internet freedom
See also: Culture of fear and Great Firewall


Internet censorship and surveillance by country (2018)^{[149][150][151][152][153]}

Pervasive   Substantial

Selective   Little or none

  Unclassified / No data
Some governments, such as those of Burma, Iran, North Korea, Mainland China, Saudi Arabia and the United Arab Emirates, restrict access to content on the Internet within their territories, especially to political and religious content, with domain name and keyword filters.^[154]
In Norway, Denmark, Finland, and Sweden, major Internet service providers have voluntarily agreed to restrict access to sites listed by authorities. While this list of forbidden resources is supposed to contain only known child pornography sites, the content of the list is secret.^[155] Many countries, including the United States, have enacted laws against the possession or distribution of certain material, such as child pornography, via the Internet, but do not mandate filter software. Many free or commercially available software programs, called content-control software are available to users to block offensive websites on individual computers or networks, in order to limit access by children to pornographic material or depiction of violence.
Performance
As the Internet is a heterogeneous network, the physical characteristics, including for example the data transfer rates of connections, vary widely. It exhibits emergent phenomena that depend on its large-scale organization.^[156]
Traffic volume