Content-control software - AbsoluteAstronomy.com

Content-control software, also known as censorware or web filtering software, is a term for software

Computer software

Computer software, or just software, is a collection of computer programs and related data that provide the instructions for telling a computer what to do and how to do it....

designed and optimized for controlling what content is permitted to a reader, especially when it is used to restrict material delivered over the Web

World Wide Web

The World Wide Web is a system of interlinked hypertext documents accessed via the Internet...

. Content-control software determines what content will be available.

The restrictions can be applied at various levels: a government can attempt to apply them nationwide (see Internet censorship

Internet censorship

Internet censorship is the control or suppression of the publishing of, or access to information on the Internet. It may be carried out by governments or by private organizations either at the behest of government or on their own initiative...

), or they can, for example, be applied by an ISP to its clients, by an employer to its personnel, by a school to its students, by a library to its visitors, by a parent to a child's computer, or by an individual user to his or her own computer.

The motive is often to prevent persons from viewing content which the computer's owner(s) or other authorities may consider objectionable; when imposed without the consent of the user, content control can constitute censorship

Censorship

thumb|[[Book burning]] following the [[1973 Chilean coup d'état|1973 coup]] that installed the [[Military government of Chile |Pinochet regime]] in Chile...

. Some content-control software includes time control functions that empowers parents to set the amount of time that child may spend accessing the Internet

Internet

The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...

or playing games or other computer activities.

In some countries, such software is ubiquitous. In Cuba

Censorship in Cuba

Censorship in Cuba has been reported on extensively, and resulted in European Union sanctions as well as statements of protest from groups, governments, and noted individuals....

, if a computer user at a government controlled Internet cafe types certain words, the word processor or browser is automatically closed, and a "state security" warning is given.

Terminology

This article uses the term "content control", a term also used on occasion by CNN

CNN

Cable News Network is a U.S. cable news channel founded in 1980 by Ted Turner. Upon its launch, CNN was the first channel to provide 24-hour television news coverage, and the first all-news television channel in the United States...

, Playboy
Playboy
Playboy is an American men's magazine that features photographs of nude women as well as journalism and fiction. It was founded in Chicago in 1953 by Hugh Hefner and his associates, and funded in part by a $1,000 loan from Hefner's mother. The magazine has grown into Playboy Enterprises, Inc., with...

magazine the San Francisco Chronicle
San Francisco Chronicle
thumb|right|upright|The Chronicle Building following the [[1906 San Francisco earthquake|1906 earthquake]] and fireThe San Francisco Chronicle is a newspaper serving primarily the San Francisco Bay Area of the U.S. state of California, but distributed throughout Northern and Central California,...

and the New York Times. However, two other terms, censorware and web filtering, while more controversial, are often used. Nannyware has also been used in both product marketing and by the media.

Companies that make products that selectively block Web sites do not refer to these products as censorware, and prefer terms such as "Internet filter" or "URL Filter"; in the specialized case of software specifically designed to allow parents to monitor and restrict the access of their children, "parental control software" is also used. Some products log all sites that a user accesses and rates them based on content type for reporting to an "accountability partner" of the person's choosing, and the term accountability software

Accountability software

Accountability software, or Internet accountability software, is a type of computer software that provides detailed reports that account for one's actions on the Internet.- Concept :...

is used. Internet filters, parental control software, and/or accountability software may also be combined into one product.

Those critical of such software, however, use the term "censorware" freely: consider the Censorware Project, for example. The use of the term censorware in editorials criticizing makers of such software is widespread and covers many different varieties and applications: Xeni Jardin

Xeni Jardin

Xeni Jardin is an American weblogger, digital media commentator, and tech culture journalist. She is known for her position as co-editor of the collaborative weblog Boing Boing, as a contributor to Wired magazine and Wired News, and as a correspondent for the National Public Radio show Day to Day...

used the term in a 9 March 2006 editorial in the New York Times when discussing the use of American-made filtering software to suppress content in China; in the same month a high school student used the term to discuss the deployment of such software in his school district.
In general, outside of editorial pages as described above, traditional newspapers do not use the term censorware in their reporting, preferring instead to use terms such as content filter, content control, or web filtering; the New York Times and the Wall Street Journal both appear to follow this practice. On the other hand, Web-based newspapers such as CNET

CNET

CNET is a tech media website that publishes news articles, blogs, and podcasts on technology and consumer electronics. Originally founded in 1994 by Halsey Minor and Shelby Bonnie, it was the flagship brand of CNET Networks and became a brand of CBS Interactive through CNET Networks' acquisition...

use the term in both editorial and journalistic contexts, for example "Windows Live to Get Censorware."

Types of filtering

Filters can be implemented in many different ways: by a software program on a personal computer or by servers providing Internet access. Choosing an Internet service provider

Internet service provider

An Internet service provider is a company that provides access to the Internet. Access ISPs directly connect customers to the Internet using copper wires, wireless or fiber-optic connections. Hosting ISPs lease server space for smaller businesses and host other people servers...

(ISP) that blocks objectionable material before it enters the home can help parents who worry about their children viewing objectionable content.

Most content control software is marketed to organizations or parents. It is, however, also advertised on occasion to facilitate self-censorship by people struggling with Internet addiction. Those obsessed by online pornography or gambling, chat rooms or the Internet in general, may wish to prevent or restrict their own access. A number of accountability software

Accountability software

Accountability software, or Internet accountability software, is a type of computer software that provides detailed reports that account for one's actions on the Internet.- Concept :...

products marketed as self-censorship or accountability software. These are promoted at churches and via religious media.

Opinions as to when this software is moral (and sometimes legal) to use vary widely with individual people being strongly in favor and against the same software used in different scenarios.

Client-side filters: This type of filter is installed as software on your computer. This filter can be customized to meet a family's needs. This filter can be disabled only by someone with the password. Client-side filters usually work well in places like libraries, because only some access points need to be filtered, for instance, the computers in the children's playing and reading section.

Content-limited (or filtered) ISPs: Content-limited (or filtered) ISPs are Internet service providers that offer access to only a set portion of Internet content. Anyone who subscribes to this type of service is subject to the same type of restrictions. These types of filters are especially designed for kids. It offers webpages that have been carefully reviewed multiple times and assessed for their appropriateness and safety. Content, entertainment, and education are key aspects as well. There are strict rules for those who break chat room and bulletin board rules. Those who break the rules are uninvited. Email and instant messages can only be received from specified parties.

Content limited ISPs that are intended for both children and adults allows access to almost everything, except what the ISP considers inappropriate. Limits and monitoring on email are very rare or do not exist at all. There are ISPs that provide both filtered/unfiltered access as well. Filtered access is available when there are ISPs that offer parental controls and passwords.

Server filter-sides: These servers are in demand and very useful in institutional settings, such as schools and library systems. All users are subject to the access policy defined by the institution. The filtering comes from the institution's ISPs directly or from the institution itself. The filtering can be customized, so a school district's high school library can have a different filtering profile than the district's junior high school library.

Search-engine filters: Many search engines, such as Google and Alta Vista offer users the option of turning on a safety filter. When this safety filter is activated, it filters out the inappropriate links from all of the search results. If one knows the actual URL of a website that features sexual explicit or 18 + content, they have the ability to access it without using a search engine. Engines like Lycos, Yahoo, and Bing offer kid-oriented versions of their engines that permit only children friendly websites.

Pros and cons

Overblocking: A filter that is highly effective at taking out content can be described as over blocking. Over blocking can filter out very important and acceptable material, such as health related information. Still, in many cases parents will still accept over blocking just to prevent exposure to other sites.

Underblocking: Whenever new information is uploaded to the Internet, filters can under block content if the people responsible for the parties do not update their systems.

Default Setting: The default setting has the ability to block out many categories from the Internet entirely. Some of these categories include: sexual images, nudity, artwork showing nudity, sex education, violence, weapons, drugs, alcohol, types of abortions, homosexual lifestyles and many more.

Morality and opinion

Many would disapprove of government filtering viewpoints on moral or political issues, agreeing that this could become support for propaganda

Propaganda

Propaganda is a form of communication that is aimed at influencing the attitude of a community toward some cause or position so as to benefit oneself or one's group....

. Many would also find it unacceptable that an ISP, whether by law or by the ISP's own choice, should deploy such software without allowing the users to disable the filtering for their own connections.

Critics argue that content-filtering software allows private companies to censor as they please. (See Religious or political censorship, below). They further argue that government encouragement of content filtering, or legal requirements for content-labeling software, would be equivalent to censorship.

Some people contrast content-control with censoring, claiming that limiting the content one can view is similar to how communist governments limit the content its citizens can view in order to promote one idea. They argue that there is a chance for the content-filtering software to be abused.

Legal actions

In 1998, a United States federal district court in Virginia ruled that the imposition of mandatory filtering in a public library violates the First Amendment of the U.S. Bill of Rights.

In 1996 the US Congress passed the Communications Decency Act

Communications Decency Act

The Communications Decency Act of 1996 was the first notable attempt by the United States Congress to regulate pornographic material on the Internet. In 1997, in the landmark cyberlaw case of Reno v. ACLU, the United States Supreme Court struck the anti-indecency provisions of the Act.The Act was...

, banning indecency on the Internet. Civil liberties groups challenged the law under the First Amendment

First Amendment to the United States Constitution

The First Amendment to the United States Constitution is part of the Bill of Rights. The amendment prohibits the making of any law respecting an establishment of religion, impeding the free exercise of religion, abridging the freedom of speech, infringing on the freedom of the press, interfering...

and in 1997 the Supreme Court

Supreme Court of the United States

The Supreme Court of the United States is the highest court in the United States. It has ultimate appellate jurisdiction over all state and federal courts, and original jurisdiction over a small range of cases...

ruled in their favor. Part of the civil liberties argument, especially from groups like the Electronic Frontier Foundation

Electronic Frontier Foundation

The Electronic Frontier Foundation is an international non-profit digital rights advocacy and legal organization based in the United States...

, was that parents who wanted to block sites could use their own content-filtering software, making government involvement unnecessary.

In the late 1990s, groups such as the Censorware Project began reverse-engineering the content-control software and decrypting the blacklists to determine what kind of sites the software blocked. This led to legal action alleging violation of the "Cyber Patrol" license agreement. They discovered that such tools routinely blocked unobjectionable sites while also failing to block intended targets. (See Over-zealous filtering, below).

Some content-control software companies responded by claiming that their filtering criteria were backed by intensive manual checking. The companies' opponents argued, on the other hand, that performing the necessary checking would require resources greater than the companies possessed and that therefore their claims were not valid.

Over-zealous filtering

Content-control software was mentioned as blocking access to Beaver College before its name change to Arcadia University

Arcadia University

Arcadia University is a private university located in Glenside, Pennsylvania, on the outskirts of Philadelphia. A master's university by Carnegie Classification, the university has a co-educational student population of more than 4,000. The university was ranked 25th in the master's universities in...

. Another example was the filtering of Horniman Museum

Horniman Museum

The Horniman Museum is a museum in Forest Hill, South London, England. Commissioned in 1898, it opened in 1901 and was designed by Charles Harrison Townsend in the Arts and Crafts style....

Religious, anti-religious, and political censorship

Many types of content-control software have been shown to block sites based on the religious and political leanings of the company owners. Examples include blocking several religious sites (including the Web site of the Vatican), many political sites, and sites about gay/lesbians. X-Stop was shown to block sites such as the Quaker

Quaker Oats Company

The Quaker Oats Company is an American food conglomerate based in Chicago. It has been owned by Pepsico since 2001.-History:Quaker Oats was founded in 1901 by the merger of four oat mills:...

web site, the National Journal of Sexual Orientation Law, the Heritage Foundation

Heritage Foundation

The Heritage Foundation is a conservative American think tank based in Washington, D.C. Heritage's stated mission is to "formulate and promote conservative public policies based on the principles of free enterprise, limited government, individual freedom, traditional American values, and a strong...

, and parts of The Ethical Spectacle. CYBERsitter blocks out sites like National Organization for Women

National Organization for Women

The National Organization for Women is the largest feminist organization in the United States. It was founded in 1966 and has a membership of 500,000 contributing members. The organization consists of 550 chapters in all 50 U.S...

. Nancy Willard, an academic researcher and attorney, pointed out that many U.S. public schools and libraries use the same filtering software that many Christian organizations use. Cyber Patrol, a product developed by The Anti-Defamation League and Mattel's The Learning Company, has been found to block not only political sites it deems to be engaging in 'hate speech' but also human rights web sites, such as Amnesty International's web page about Israel and gay-rights web sites, such as glaad.org.

Content labeling

Content labeling may be considered another form of content-control software. In 1994, the Internet Content Rating Association

Internet Content Rating Association

Internet Content Rating Association was an international non-profit organization with offices in the United States and the United Kingdom...

(ICRA) — now part of the Family Online Safety Institute

Family Online Safety Institute

The Family Online Safety Institute, or FOSI, is an international nonprofit organization. It is registered as a 501 tax-deductible nonprofit charity in the United States and a registered charity in the United Kingdom. FOSI was founded in February 2007 by Stephen Balkam, who previously created the...

— developed a content rating system for online content providers. Using an online questionnaire a webmaster describes the nature of his web content. A small file is generated that contains a condensed, computer readable digest of this description that can then be used by content filtering software to block or allow that site.

ICRA labels come in a variety of formats. These include the World Wide Web Consortium's Resource Description Framework

Resource Description Framework

The Resource Description Framework is a family of World Wide Web Consortium specifications originally designed as a metadata data model...

(RDF) as well as Platform for Internet Content Selection

Platform for Internet Content Selection

The Platform for Internet Content Selection is a specification created by W3C that uses metadata to label webpages to help parents and teachers control what children and students can access on the Internet. The W3C Protocol for Web Description Resources project integrates PICS concepts with RDF...

(PICS) labels used by Microsoft

Microsoft

Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...

's Internet Explorer

Internet Explorer

Windows Internet Explorer is a series of graphical web browsers developed by Microsoft and included as part of the Microsoft Windows line of operating systems, starting in 1995. It was first released as part of the add-on package Plus! for Windows 95 that year...

Content Advisor.

ICRA labels are an example of self-labeling. Similarly, in 2006 the Association of Sites Advocating Child Protection (ASACP)

Association of Sites Advocating Child Protection (ASACP)

The is a non-profit organization that fights Internet child pornography and works to help parents prevent children from viewing age-inappropriate material online....

initiated the Restricted to Adults self-labeling initiative. ASACP members were concerned that various forms of legislation being proposed in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

were going to have the effect of forcing adult companies to label their content. The RTA label, unlike ICRA labels, does not require a webmaster to fill out a questionnaire or sign up to use. Like ICRA the RTA label is free. Both labels are recognized by a wide variety of content-control software.

The Voluntary Content Rating (VCR) system was devised by Solid Oak Software for their CYBERsitter filtering software, as an alternative to the PICS system, which some critics deemed too complex. It employs HTML

HTML

HyperText Markup Language is the predominant markup language for web pages. HTML elements are the basic building-blocks of webpages....

metadata

Meta element

Meta elements are the HTML or XHTML <meta … > element used to provide structured metadata about a Web page. Multiple elements are often used on the same page: the element is the same, but its attributes are different...

tags embedded within web page documents to specify the type of content contained in the document. Only two levels are specified, mature and adult, making the specification extremely simple.

US

The use of Internet filters or content-control software varies widely in public libraries in the United States, since Internet use policies are established by the local library board. Many libraries adopted Internet filters after Congress conditioned the receipt of universal service discounts on the use of Internet filters through the Children's Internet Protection Act

Children's Internet Protection Act

The Children's Internet Protection Act requires that K-12 schools and libraries in the United States use Internet filters and implement other measures to protect children from harmful online content as a condition for the receipt of certain federal funding...

(CIPA). Other libraries do not install content control software, believing that acceptable use policies and educational efforts address the issue of children accessing age-inappropriate content while preserving adult users' right to freely access information. Some libraries use Internet filters on computers used by children only. Some libraries that employ content-control software allow the software to be deactivated on a case-by-case basis on application to a librarian; libraries that are subject to CIPA are required to have a policy that allows adults to request that the filter be disabled without having to explain the reason for their request.

Many legal scholars believe that a number of legal cases, in particular Reno v. American Civil Liberties Union
Reno v. American Civil Liberties Union
Reno v. American Civil Liberties Union, , is a United States Supreme Court case, in which all nine Justices of the Court voted to strike down anti-indecency provisions of the Communications Decency Act , finding they violated the freedom of speech provisions of the First Amendment. Two Justices...

, established that the use of content-control software in libraries is a violation of the First Amendment. The Children's Internet Protection Act [CIPA] and the June 2003 case United States v. American Library Association
United States v. American Library Association
United States v. American Library Association, 539 U.S. 194 , was a decision in which the United States Supreme Court ruled that the United States Congress has the authority to require public schools and libraries receiving E-Rate discounts to install web filtering software as a condition of...

found CIPA constitutional as a condition placed on the receipt of federal funding, stating that First Amendment concerns were dispelled by the law's provision that allowed adult library users to have the filtering software disabled, without having to explain the reasons for their request. The plurality decision left open a future "as-applied" Constitutional challenge, however. In November 2006, a lawsuit was filed against the North Central Regional Library District (NCRL) in Washington State for its policy of refusing to disable restrictions upon requests of adult patrons, but CIPA was not challenged in that matter. In May 2010, the Washington State Supreme Court provided an opinion after it was asked to certify a question referred by the United States District Court for the Eastern District of Washington: “Whether a public library, consistent with Article I, § 5 of the Washington Constitution, may filter Internet access for all patrons without disabling Web sites containing constitutionally-protected speech upon the request of an adult library patron.” The Washington State Supreme Court ruled that NCRL’s internet filtering policy did not violate Article I, Section 5 of the Washington State Constitution. The Court said: “It appears to us that NCRL’s filtering policy is reasonable and accords with its mission and these policies and is viewpoint neutral. It appears that no article I, section 5 content-based violation exists in this case. NCRL’s essential mission is to promote reading and lifelong learning. As NCRL maintains, it is reasonable to impose restrictions on Internet access in order to maintain an environment that is conducive to study and contemplative thought.” The case now returns to federal court.

In March 2007, Virginia passed a law similar to CIPA that requires public libraries receiving state funds to use content-control software. Like CIPA, the law requires libraries to disable filters for an adult library user when requested to do so by the user.

Australia

The Australian Internet Safety Advisory Body has information about "practical advice on Internet safety, parental control and filters for the protection of children, students and families" that also includes public libraries.

NetAlert, the software made available free of charge by the Australian government, was allegedly cracked by a 16 year old student, Tom Wood, less than a week after its release in August 2007. Wood supposedly bypassed the $84 million filter in about half an hour to highlight problems with the government's approach to Internet content filtering.

The Australian Government has introduced legislation that requires ISP's to "restrict access to age restricted content (commercial MA15+ content and R18+ content) either hosted in Australia or provided from Australia" that was due to commence from 20 January 2008, known as Cleanfeed

Cleanfeed (content blocking system)

Cleanfeed is the name given to privately administered ISP level content filtering systems operating in the United Kingdom and Canada. It is also the name of a proposed mandatory Australian ISP level content filtering system which is undergoing testing...

.

Cleanfeed is a proposed mandatory ISP level content filtration system. It was proposed by the Beazley

Kim Beazley

In the October 1998 election, Labor polled a majority of the two-party vote and received the largest swing to a first-term opposition since 1934. However, due to the uneven nature of the swing, Labor came up eight seats short of making Beazley Prime Minister....

led Australian Labor Party

Australian Labor Party

The Australian Labor Party is an Australian political party. It has been the governing party of the Commonwealth of Australia since the 2007 federal election. Julia Gillard is the party's federal parliamentary leader and Prime Minister of Australia...

opposition in a 2006 press release, with the intention of protecting children who were vulnerable due to claimed parental computer illiteracy. It was announced on 31 December 2007 as a policy to be implemented by the Rudd

Kevin Rudd

Kevin Michael Rudd is an Australian politician who was the 26th Prime Minister of Australia from 2007 to 2010. He has been Minister for Foreign Affairs since 2010...

ALP government, and initial tests in Tasmania

Tasmania

Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...

have produced a 2008 report. Cleanfeed is funded in the current budget, and is moving towards an Expression of Interest for live testing with ISPs in 2008. Public opposition and criticism have emerged, led by the EFA

EFA

EFA may refer to:In law:*Elder Financial Abuse a term describing a criminal act against seniors and other dependents.In organizations:*Egyptian Football Association, the governing body of association football in Egypt...

and gaining irregular mainstream media attention, with a majority of Australians reportedly "strongly against" its implementation. Criticisms include its expense, inaccuracy (it will be impossible to ensure only illegal sites are blocked) and the fact that it will be compulsory, which can be seen as an intrusion on free speech rights. Another major criticism point has been that although the filter is claimed to stop certain materials, the underground rings dealing in such materials will not be affected. The filter might also provide a false sense of security for parents, who might supervise children less while using the Internet, achieving the exact opposite effect. Cleanfeed is a responsibility of Senator Conroy's

Stephen Conroy

Stephen Michael Conroy is an Australian politician and the current Minister for Broadband, Communications and the Digital Economy in the Gillard Ministry...

portfolio.

Denmark

In Denmark it is stated policy that it will "prevent inappropriate Internet sites from being accessed from children's libraries across Denmark." "'It is important that every library in the country has the opportunity to protect children against pornographic material when they are using library computers. It is a main priority for me as Culture Minister to make sure children can surf the net safely at libraries,' states Brian Mikkelsen in a press-release of the Danish Ministry of Culture."

Bypassing filters

Content filtering in general can "be bypassed entirely by tech-savvy individuals" Blocking content on circumvention advice "[will not]...guarantee that users won't eventually be able to find a way around the filter."

Some software may be bypassed successfully by using alternative protocols such as FTP

File Transfer Protocol

File Transfer Protocol is a standard network protocol used to transfer files from one host to another host over a TCP-based network, such as the Internet. FTP is built on a client-server architecture and utilizes separate control and data connections between the client and server...

or telnet

TELNET

Telnet is a network protocol used on the Internet or local area networks to provide a bidirectional interactive text-oriented communications facility using a virtual terminal connection...

or HTTPS

Https

Hypertext Transfer Protocol Secure is a combination of the Hypertext Transfer Protocol with SSL/TLS protocol to provide encrypted communication and secure identification of a network web server...

, conducting searches in a different language, using a proxy server

Proxy server

In computer networks, a proxy server is a server that acts as an intermediary for requests from clients seeking resources from other servers. A client connects to the proxy server, requesting some service, such as a file, connection, web page, or other resource available from a different server...

or a circumventor such as Psiphon

Psiphon

Psiphon is a web proxy designed to help Internet users securely bypass the content-filtering systems used to censor the internet by governments in places like China, North Korea, Iran, Syria, Myanmar, Saudi Arabia, United Arab Emirates, Vietnam, Pakistan, Belarus' and others...

. Also cached web pages returned by Google or other searches could bypass some controls as well. Web syndication services may provide alternate paths for content. Some of the more poorly-designed programs can be shut down by killing their processes: for example, in Microsoft Windows

Microsoft Windows

Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...

through the Windows Task Manager

Task manager

A task manager is a program used to provide information about the processes and programs running on a computer, as well as the general status of the computer. It can also be used to terminate processes and programs, as well as change the processes priority...

, or in Mac OS X

Mac OS X

Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...

using Force Quit or Activity Monitor

Activity Monitor

Activity Monitor is a task manager, a utility for performing different tasks to a computer processes, in the Mac OS X operating system. Some of its functions include:*Quitting or "killing" a computer process*Viewing the computer's CPU load...

. Numerous workarounds and counters to workarounds from content-control software creators exist.
Google

Google

Google Inc. is an American multinational public corporation invested in Internet search, cloud computing, and advertising technologies. Google hosts and develops a number of Internet-based services and products, and generates profit primarily from advertising through its AdWords program...

services are often blocked by filters, but these may most often be bypassed by using https:// in place of http:// since content filtering software is not able to interpret content under secure connections (in this case SSL).

Many content filters have an option which allows authorized people to bypass the content filter. This is especially useful in environments where the computer is being supervised and the content filter is aggressively blocking Web sites that need to be accessed.

An encrypted VPN can also be used as means of bypassing content control software, especially if the content control software is installed on an Internet gateway or firewall.

Products and services

Some ISPs offer parental control options. Some offer security software which includes parental controls. Mac OS X v10.4

Mac OS X v10.4

Mac OS X v10.4 Tiger is the fifth major release of Mac OS X, Apple's desktop and server operating system for Macintosh computers. Tiger was released to the public on 29 April 2005 for US$129.95 as the successor to Mac OS X Panther , which had been released 18 months earlier...

offers parental controls for several applications (Mail

Mail (application)

Mail is an email program included with Apple Inc.'s Mac OS X operating system. Originally developed by NeXT as NeXTMail, a part of their NeXTSTEP operating system, it was adapted, following Apple's acquisition of NeXT, to become OS X's Mail application.Mail uses the SMTP, POP3, and IMAP protocols,...

, Finder

Macintosh Finder

The Finder is the default file manager used on Mac OS and Mac OS X operating systems; it is responsible for the overall user-management of files, disks, network volumes and the launching of other applications...

, iChat

IChat

iChat is an instant messaging software application developed by Apple Inc. exclusively for its Mac OS X operating system. It has audio, video and screen-sharing capabilities as well as text messaging...

, Safari

Safari (web browser)

Safari is a web browser developed by Apple Inc. and included with the Mac OS X and iOS operating systems. First released as a public beta on January 7, 2003 on the company's Mac OS X operating system, it became Apple's default browser beginning with Mac OS X v10.3 "Panther". Safari is also the...

& Dictionary

Dictionary (software)

Dictionary is an application developed by Apple for its Macintosh computers. It was introduced with Mac OS X v10.4 "Tiger", and provides definitions and synonyms from the New Oxford American Dictionary, 2nd Edition and Oxford American Writer's Thesaurus, 2nd Edition...

). Microsoft's Windows Vista

Windows Vista

Windows Vista is an operating system released in several variations developed by Microsoft for use on personal computers, including home and business desktops, laptops, tablet PCs, and media center PCs...

operating system also includes content-control software.

Content filtering technology exists in two major forms: application gateway

Application-level gateway

In the context of computer networking, an application-level gateway consists of a security component that augments a firewall or NAT employed in a computer network...

or packet inspection

Deep packet inspection

Deep Packet Inspection is a form of computer network packet filtering that examines the data part of a packet as it passes an inspection point, searching for protocol non-compliance, viruses, spam, intrusions or predefined criteria to decide if the packet can...

. For HTTP access the application gateway is called a web-proxy or just a proxy. Such web-proxies can inspect both the initial request and the returned web page using arbitrarily complex rules and will not return any part of the page to the requester until a decision is made. In addition they can make substitutions in whole or for any part of the returned result. Packet inspection filters do not initially interfere with the connection to the server but inspect the data in the connection as it goes past, at some point the filter may decide that the connection is to be filtered and it will then disconnect it by injecting a TCP-Reset or similar faked packet. The two techniques can be used together with the packet filter monitoring a link until it sees an HTTP connection starting to an IP address that has content that needs filtering. The packet filter then redirects the connection to the web-proxy which can perform detailed filtering on the website without having to pass through all unfiltered connections. This combination is quite popular