Whats wrong with list-based filtering?
There are several problems with filtering based on lists of sites to be blocked. First, these lists are incomplete. Due to the decentralized nature of the Internet, it’s practically impossible to definitively search all Internet sites for “objectionable” material. Even with a paid staff searching for sites to block, software vendors cannot hope to identify all sites that meet their blocking criteria. Furthermore, since new web sites are constantly appearing, even regular updates from the software vendor will not block out all adult web sites. Each updated list will be obsolete as soon as it is released, as any as any site that appears after the update will not be on the list, and will not be blocked. The volatility of individual sites is yet another potential cause of trouble. Adult material might be added to (or removed from) a site soon after the site is added to (or removed from) a list of blocked sites. Blocking lists also raise problems by withholding information from users, who m
