What Is a Monitor Filter?

Internet filters are software that restricts or controls the content that Internet users can access, especially when used to restrict content that is transmitted through the Internet, e-mail, or other means through the Internet. Internet filters determine which content passes or is blocked.

The motivation for doing this is often to prevent access to content that the host of the computer finds offensive. This review mechanism can be characterized as an Internet review mechanism when implemented without the user's consent. Some content control software has a time control function that enables parents to control the time that their children may spend on the Internet or other computers.

In some countries, this software is ubiquitous. In Cuba, if a user enters a specific word in a government-controlled Internet cafe, the word processor or browser will automatically close and a "national security" warning will be issued.

Companies that make products that selectively block websites don't call these products censorship software, and prefer terms such as "Internet filters" or "URL filters"; specifically designed to allow parents to monitor and restrict them In the special case of software accessed by children, "parental control software" is also used. Some products record all websites visited by a user and rate them based on the type of content in order to report to the "accountability partner" that user selects and use the term accountability software. Internet filters, parental control software and / or accountability software can also be combined into one product.

However, those who criticize such software are free to use the term "review software": for example, consider the Censorware project. The use of the term "censorship software" in editorials criticizing such software makers is widespread and covers many different varieties and applications: Xeni Jardin discussed the use of American manufacturing in a New York Times editorial on March 9, 2006 Filters that suppress Chinese content; in the same month, a high school student used the term to discuss deploying such software in his school district.

In general, outside of the above editing pages, traditional newspapers do not use the term "censorship software" in their coverage, but tend to use less publicly contested terms such as "content filtering", "content control" or " Web filtering "; both the New York Times and the Wall Street Journal seem to follow this approach. On the other hand, web-based newspapers such as CNET use the term in both editorial and news contexts, such as "Windows Live acquisition censorship software." ^[1]

Filters can be implemented in many different ways: through software on a personal computer, through network infrastructure, such as

Content tags can be viewed as another form of content control software. In 1994, the Internet Content Rating Association (ICRA) is currently part of the Home Online Security Institute, which develops a content rating system for online content providers. Using online questionnaires, webmasters can describe the nature of their web content. Generate a small file with a condensed computer-readable summary of this description, which can then be used by content filtering software to block or allow the site.

ICRA tags come in many formats. Including the World Wide Web Consortium

Content filtering can often be "bypassed completely by tech-savvy people." Blocking content on the device "guarantees that users ultimately cannot find a way to bypass the filter."

Some software can be successfully bypassed by using alternative protocols such as

Some ISPs offer parental control options. Some provide security software that includes parental controls. Mac OS X v10.4 provides parental control for several applications (Mail, Finder, iChat, Safari, and Dictionary). Microsoft's Windows Vista operating system also includes content control software.

There are two main forms of content filtering technology: application gateway or packet inspection. For HTTP access, the application gateway is called a web proxy or just a proxy. Such a network proxy can use arbitrarily complex rules to inspect the initial request and the returned web page, and will not return any part of the page to the requester before making a decision. In addition, they can replace the whole or any part that returns results. The packet inspection filter does not initially interfere with the server's connection, but checks the data in the connection as the connection passes. At some point, the filter may decide that the connection will be filtered and then it will be reset by injecting Similar forged packets. Both techniques can be used with packet filters to monitor links until it sees that the HTTP connection starts to an IP address with content that needs to be filtered. The packet filter then redirects the connection to a web proxy, which can perform detailed filtering on the website without having to go through all unfiltered connections. This combination is very popular because it can significantly reduce system costs.

Gateway-based content control software may be more difficult to bypass than desktop software because users do not have physical access to filtering devices. But many of the techniques in the Bypassing filter section still work.