Internet Filters

An internet filter is a software or hardware product designed to prevent access to certain undesirable areas of the internet.  So how do they work? Some work by comparing site requests with a list of previously known bad URLs and preventing viewing if they are listed.  Other filters scan incoming data and blocks it if it contains undesirable keywords, file types, or other perimeters.  Sometimes the parent can control or create the list of keywords or sites filtered.  Internet filters can compare to a parental controlled Children's Browser.  A Children's Browser is a special parent controlled browser, like Internet Explorer or Netscape, which allows access only to sites that are known to be suitable for children.  A browser operates with its own set of known good sites, and will not allow access to any others.  They have email/chat filtering ability that do not allow "rude words".  A password can be set up that prevents a child from exiting and using a normal browser.  An internet filter compares to the Children's Browser because an internet filter allows general "surfing" to take place with the exception of filtered sites.  This is important for older children and parents when access to purely child safe sites would typically be too limiting.  The internet filter becomes useful because it is not possible to maintain a database of all sites that are unsuitable. 

An Internet Filter is not 100% effective.  Sometimes, an unwanted site may appear to the user if they make a concerted effort to find one that does not trigger the filtering device, or even if they are not looking for one.  There are many sites that border on obscenity depending on one's perspective.  Medical gynecology sites may be considered essential for research by some, or a religious site may be perfect for one person but offensive to another.  Many times, people's interpretations vary from one to another, so internet filters may be inaccessible if one finds it offensive.  There are two different types of filters.  One is a Client-Based filter.  This is generally a software product which runs on the user's machine at the same time as the browser that is used for internet access.  The filter is responsible for rejecting inappropriate materials before they are handed to the browser.  The other is a  Server-Based filter.  This provides the filtering component remotely to the user machine, by the internet or a network.  The filtering is done before the data is sent to the client's machine.  This way, the filtering component cannot find a way around.  it is sometimes possible to bypass a client-based filter with advanced network skills.  A Server-Based filter is usually more expensive and complicated often requires an ongoing cost for use of the remote filtering service, where as Client-Based filter is usually a stand-alone product requiring no maintenance fees.  

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