Information Technology Reference
In-Depth Information
Censorship and Filtering
Censorship
is the act of preventing something from being printed
or heard. Historically, censorship has been used to prevent important
information from reaching the population at large by controlling what
can be printed or broadcast. Censorship is sometimes implemented by
governments so they can control the flow of information for political
or military reasons. For example, writing that is deemed to be obscene
or advocates that citizens break the country's existing laws might be
censored. Individuals or companies can also apply forms of censorship by
not allowing certain types of information to be published. For example,
if you post a negative review of a product on the manufacturer's website,
your view may be deleted; this is an example of corporate censorship.
censorship
The act of suppressing speech or
not allowing certain communications to be made
public.
Filtering is a form of censorship performed by software.
Filtering
means to prevent something from getting through. For example, when
you filter water, you remove all the impurities, making it safe to drink.
Similarly, when you filter the Internet, you exclude certain categories
of content from general access. For example, a parent might install web
filtering software on a child's computer to prevent the child from access-
ing websites with graphic violent content, or a coffee shop might use
filtering to prevent its patrons from accessing adult-themed sites when
using the store's Internet connection. Companies also may filter their
employees' web usage at work, such as blocking social networking sites
like Facebook to improve productivity.
filtering
Preventing something from getting
through—in this case, content.
Web filtering is accomplished by using a
proxy server
—that is, a server
that sits between the user's web browser and the Internet and manages
all requests for content.
proxy server
A server that sits between the
user's web browser and the Internet that intercepts
all requests for web pages and processes those
requests.
When users attempt to access a filtered site, a message is displayed in
their browser, notifying them that the request is denied. Figure 12.2
shows a list of blocked site categories on a proxy server.
Figure.12 2
A list of blocked categories on a proxy server.
