Censorware is a term used pejoratively to describe software that filters out undesirable Web sites or content. Examples include Cybersitter, N2H2, Netnanny, Surfwatch, and Wisechoice. This kind of software is designed to restrict an individual's ability to send or receive certain types of information, and for that reason its use (in public libraries, for example) is a contentious issue. Organizations such as the American Civil Liberties Union (ACLU) and the Electronic Privacy Information Center (EPIC) argue that the use of censorware conflicts with individual rights to freedom of expression and freedom of association, as mandated by the United States constitution.
There are a number of problems with censorware, quite apart from the question of whether or not it infringes upon individual rights to access to information. Censorware blocks certain Web site categories and also uses language-based criteria to define undesirable content. Given the ambiguous nature of isolated parts of speech, words and phrases that are deemed unacceptable in one context may be completely innocuous in another. Such ambiguity can lead to innocent material being blocked , or conversely, offensive material passing through the program's filters. In 2000, the Digital Freedom Network (DFN), an Internet rights organization, hosted a contest for the most ludicrous example of censorware at work. The contest winner was a student who was denied access to his high school's web site from within the school's library because his search term included the word "high."
Bobson Wong, DFN's executive director, maintains that parents should supervise their children rather than counting on censorware to do it for them. According to Wong, "The bottom line is that filtering software is no substitute for human judgment."