Internet Blocking

Blocking Technology

Content can be blocked by individual users through their web browsers, computer operating systems, or client-side computer programs such as NetNanny or by Internet service providers (ISPs), network managers, or search engines. The crudest forms restrict Internet access by configuring operating systems to require passwords when logging on or opening web browsers, or with tamper-proof physical locks that disable hardwired Internet connections or power cords. Address filtering employs black lists that block forbidden web addresses or white lists that allow access only to acceptable websites. Keyword filters block URLs of websites or images that contain forbidden words, such as derogatory terms used by hate groups. Content ratings of “old media” products, such as TV-MA or R-rated videos, are also used by filtering software. Collaborative filtering enlists users and content providers to participate in the filtering process by labeling content. Pattern recognition software detects nudity and might conceivably be designed to detect fistfights or hostile spoken words as well.

Efficiency

Content filtering has technical and social limitations. Both overblocking of desirable content and underblocking of unwanted material are frequent errors. Address filtering requires continual updating of black lists (or white lists). Blocking of specific content within websites, such as music and videos, relies on the content rating systems of entertainment industries that either do not incorporate violence (e.g., Recording Industry Association of America’s Parental Advisory labels) or that focus more on sex than violence (e.g., Motion Picture Association of America film ratings). Pattern recognition of video remains a significant technical challenge. Internet blocking techniques are susceptible to circumvention both by those whom they are intended to protect and by content providers. Computer-savvy children have a variety of antiblocking techniques at their disposal: passwords can be guessed, fraudulent accounts established, computers carried to outlets without parental lockouts. And tips for evading filtering software are readily available online and through youth subcultures. Content providers can disseminate new addresses that redirect users to blocked ones or copy material to new websites.

Prevalence

National surveys from the mid-2000s found that filtering software was used in a third of UK and more than half of U.S. homes. Workplace filtering through corporate firewalls is widespread, although [Page 206]it is primarily targeted to pornography and illegal activities rather than violent or aggressive content. The Children’s Internet Protection Act (CIPA) of 1999 requires filtering in U.S. schools and libraries that receive public (E-Rate) funds for computers, and filtering is universal in U.S. schools and participating public libraries. CIPA is aimed primarily at sexual content, but individual organizations determine what is appropriate content for children, so filtering of violent content also likely occurs, but the extent is unknown. Among nations, China suppresses postings about violent protests by its citizens. Egypt shut down the Internet during the Arab Spring uprising of 2011, as Iran had done in 2009, in part to prevent the spread of images of violent antigovernment protests. France and Germany block words and images related to Nazism and Holocaust denial, and the European Union is implementing automated filtering of child pornography and possible terror-related websites.

...