Filtering's Inherent Flaws
Filtering technologies, however, are prone to two simple inherent flaws: underblocking and overblocking. While technologies can be effective at blocking specific content such as high profile web sites, current technology is not able to accurately identify and target specific categorizes of content found on the billions of webpages and other Internet media including news groups, email lists, chat rooms and instant messaging. Underblocking refers to the failure of filtering to block access to all the content targeted for censorship. On the other hand, filtering technologies often block content they do not intend to block, also known as overblocking. Many blacklists are generated through a combination of manually designated web sites as well as automated searches and, thus, often contain websites that have been incorrectly classified. In addition, blunt filtering methods such as IP blocking can knock out large swaths of acceptable websites simply because they are hosted on the same IP address as a site with restricted content.
The profusion of Internet content means that Internet filtering regimes that hope to comprehensively block access to certain types of content must rely on software providers with automated content identification methods. This effectively puts control over access in the hands of private corporations that are not subject to the standards of review common in government mandates. In addition, because the filters are often proprietary, there is often no transparency in terms of the labeling and restricting of sites. The danger is most explicit when the corporations that produce content filtering technology work alongside undemocratic regimes in order to set-up nationwide content filtering schemes. Most states that implement content filtering and blocking augment commercially generated blocklists with customized lists that focus on topics and organizations that are nation or language-specific.
