Internet censorship prevents users from creating or viewing specific online content and can be done by governments, businesses, schools and even home users. Some examples of content that could be censored include materials dealing with pornography, graphic violence, terrorism and political concepts not accepted by a specific region or government. Some reasons for Internet censorship seek to protect users, such as the censoring of inappropriate content in an environment with children; other such censorship can have malicious intentions. There also are various methods that one can use to block inappropriate material, and some are more effective than others.
Each government, business, school and individual can have a different motive for using online censorship. Governments may block websites displaying material that is illegal in a specific country or websites that discuss undesirable political views. Businesses may block websites that employees could use to waste company time, including social networking, instant messaging and online game websites. Schools may block students from websites that students could use to waste time, but they also may seek to protect children from viewing content containing pornography and violence. Home users can use blocking software to keep a list of specific websites or entire categories of sites from use.
Various technical methods can be used for Internet censorship, ranging from blocking an individual user's Internet protocol (IP) address to disconnecting any physical routers that provide access to the material. IP blocking, domain name system (DNS) filtering and packet filtering are all considered partial censorship methods, because there is a chance users can bypass the blocking. For example, proxy servers are useful for circumventing most of these partial filtering techniques and reduce the security of these Internet censorship tools. The full-block method involves disconnecting routers so no one in the area can bypass the block. Some governments use the full-block method because of its reliability.
Internet censorship is a controversial issue, and it has many supporters and opponents. Those who support Internet censorship argue that it protects citizens from harmful material and can prevent political upheaval in some areas. Supporters often emphasize the importance of blocking illegal pornographic materials from children and adults as a good reason to censor online content. Opponents of Internet censorship argue that it takes away the right of free speech, that governments can use the tool to prevent citizens from knowing important information and that some can and do abuse its power.