Business is booming. The most commonly used filters in schools, like SurfControl's Cyber Patrol and N2H2's Bess, are category list-based products that filter by IP address or domain name. In the case of Cyber Patrol, human reviewers, who are parents, teachers and trained professionals, build the lists based on published criteria. We use artificial intelligence in the research process, but ALL sites added to our CyberNOT list of inappropriate content have been reviewed by a person. This is an important point because it means there is no confusion over chicken breasts and human ones.
Some products filter at the root, or domain, level.
More sophisticated filters like Cyber Patrol allow restrictions to be set at directory or page levels, so you don't have to restrict an entire website if one page contains inappropriate content. Other products used in schools offer similar categories. Filters used in schools and other institutions are usually server-based and integrate with existing network users and groups for ease of administration and security. In our case, we offer standalone versions of Cyber Patrol for parents at home and server-based solutions for schools. A new version of Cyber Patrol has been created for Microsoft's ISA Server, the latest technology for Internet servers.