How Internet Censorship Works

Internet Censorship at Home

Web filter programs like Net Nanny use blacklists to block access to Web sites with mature content.
Web filter programs like Net Nanny use blacklists to block access to Web sites with mature content.
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There's no denying that the Internet contains a lot of material that most parents wouldn't want their children to see. Whether it's pornography, hate speech, chat rooms or gambling sites, many parents worry that their children will be exposed to negative or even dangerous content. While some opponents of censorship may feel that parental supervision is the best way to keep kids safe online, many parents point out that it's difficult -- if not impossible -- to oversee a child's access to the Internet all the time.

Many parents turn to software and hardware solutions to this problem. They can purchase Web filtering programs like Net Nanny or CYBERsitter to block access to undesirable Web sites. These programs usually have a series of options parents can select to limit the sites their children can access. These options tell the program which filters to enable. For example, CYBERsitter has 35 filter categories, including pornography and social networking sites [source: CYBERsitter].

Most Web filters use two main techniques to block content: Blacklists and keyword blocking. A blacklist is a list of Web sites that the Web filter's creators have designated as undesirable. Blacklists change over time, and most companies offer updated lists for free. Any attempt to visit a site on a blacklist fails. With keyword blocking, the software scans a Web page as the user tries to visit it. The program analyzes the page to see if it contains certain keywords. If the program determines the Web page isn't appropriate, it blocks access to the page.

Another option for parents is to install a firewall. A computer firewall provides protection from dangerous or undesirable content. Firewalls can be software or hardware. They act as a barrier between the Internet and your computer network. They only let safe content through and keep everything else out. Firewalls require a little more involvement from the network administrator (in this case, a parent) than Web filtering software. Tech-savvy parents might not have a problem installing and maintaining a firewall. Others prefer to use Web filters, which do most of the work for them.

Have you ever tried to access a Web site at your workplace only to receive an intimidating message? Some companies limit the kinds of sites employees can visit. Learn about Internet censorship from the corporate standpoint on the next page.