users can instead indirectly access the page via a proxy server offering translation

features. 

As noted above, filtering companies often block loophole sites, such as caches,

anonymizers, and translation sites.  The practice of blocking loophole sites necessarily

results in a significant amount of overblocking, because the vast majority of the pages

that are cached, for example, do not contain content that would match a filtering

company's category definitions.  Filters that do not block these loophole sites, however,

may enable users to access any URL on the Web via the loophole site, thus resulting in

substantial underblocking. 

c.  The Process for  Re Reviewing  Web Pages After Their Initial Categorization

Most filtering software companies do not engage in subsequent reviews of

categorized sites or pages on a scheduled basis.  Priority is placed on reviewing and

categorizing new sites and pages, rather than on re reviewing already categorized sites

and pages.  Typically, a filtering software vendor's previous categorization of a Web site

is not re reviewed for accuracy when new pages are added to the Web site.  To the extent

the Web site was previously categorized as a whole, the new pages added to the site

usually share the categorization assigned by the blocking product vendor.  This

necessarily results in both over  and underblocking, because, as noted above, the content

of Web pages and Web sites changes relatively rapidly. 

In addition to the content on Web sites or pages changing rapidly, Web sites

themselves may disappear and be replaced by sites with entirely different content.  If an

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