Parental controls are features which may be included in digital television services, computer and video games, mobile phones and software. Parental controls fall into roughly four categories, content filters, which limit access to age appropriate content, usage controls, which constrain the usage of these devices such as placing time-limits on usage or forbidding certain types of usage, computer usage management tools, which enforces the use of certain software, and monitoring, which can track location and activity when using the devices.
Content Filters were the first popular type of parental controls to limit access to Internet content. television stations also began to introduce V-Chip technology to limit access to television content. Modern usage controls are able to restrict a range of explicit content such as explicit songs movies. They are also able to turn devices off during specific times of the day, limiting the volume output of devices, and with GPS technology becoming affordable, it is now possible to easily locate devices such as mobile phones.
Several techniques exist aimed at creating parental controls for blocking websites. Add-on parental control software may monitor API in order to observe applications such as a web browser or Internet chat application and to intervene according to certain criteria, such as a match in a database of banned words. Virtually all parental control software includes a password or other form of authentication to prevent unauthorised users from disabling it.
Techniques involving a proxy server are also used. A web browser is set to send requests for web content to the proxy server rather than directly to the web server intended. The proxy server then fetches the web page from the web server on the web browser's behalf and passes on the content to the browser. Proxy servers can inspect the data being sent and received and intervene depending on various criteria relating to content of the page or the URL being requested, for example, using a database of banned words or banned URLs. The proxy method's major disadvantage is that it requires that the client application to be configured to utilize the proxy, and if it is possible for the user to reconfigure applications to access the Internet directly rather than going through the proxy then this control is easily bypassed. Proxy servers themselves may be used to circumvent parental controls. There are other techniques used to bypass parental controls.
Computer usage management method, unlike content filters, is focused on empowering the parents to balance the computing environment for children by regulating gaming. The main idea of these applications is to allow parents to enforce learning component into the computing time of children, where children must earn gaming time while working through educational contents.
Parental controls on mobile phones
The increased use of mobile phones that include full featured internet browsers and downloadable applications has created a demand for parental controls on these mobile, smart handhelds. In November 2007, Verizon was the first carrier to offer age-appropriate content filters as well as the first to offer content-generic content filters recognizing that mobile phones were used to access all manner of content from movies and music to short-code programs and websites. In June 2009, on the iPhone OS version 3.0, Apple Computer was the first mobile device company to provide a built in mechanism on iPhone and iPod Touch devices to create age brackets for users that would block unwanted applications from being downloaded to the device.
Mobile phone software enables parents to restrict which applications their child can access while also allowing parents to monitor text messages, phone logs, MMS pictures, and other transactions occurring on their child's mobile phone, to enable parents to set time limit on the usage of mobile phones, and to track the exact location of their children as well as monitor calls in and out and the content of texts in and out.
Commonly used methods to bypass parental controls
Several methods of bypassing parental controls are commonly used. If the filtering software is located locally within the computer, all Internet software can be easily bypassed by booting up the computer in question from alternative media or with an alternative operating system. However, if the computer's BIOS is configured to disallow booting from removable media, and if changes to the BIOS are prohibited without proper authentication, then this approach is not available.
Another technique involves using external proxy servers or other servers. The user sends requests to the external server which retrieves content on the user's behalf. Filtering software may then never be able to know which URLs the user is accessing, as all communications are with the one external server and filtering software never sees any communications with the web servers from which content really originated. To counter this, filtering software may also block access to popular proxies. Additionally, filtering systems which only permit access to a set of allowed URLs will not permit access anything outside this list, including proxy servers.
Modifying the software's files is a common form of bypassing, too, as well as brute-force attacks on software passwords.
Video game systems that have used parental controls
Listed in chronological order
- PlayStation 3
- PlayStation 2 (only for DVDs)
- PlayStation Portable
- Xbox 360
- Nintendo DSi
- Nintendo 3DS
- Wii U
Operating systems with parental controls
Below is a list of operating systems which currently have built-in parental control features:
- Mac OS X (10.3-10.7)
- Windows Vista
- Windows 7
- Windows 8
- Mandriva Linux (via drakguard)
- Linux using DansGuardian either on the machine or, with Windows or Mac machines, as a server/proxy.
- Safe Internet for kids, a free live and browser-only content-filtered operating system.
- Content-control software
- David Burt
- Internet censorship
- Motion picture rating system
- Television rating system
- Videogame Rating Council
- Cable Providers and Parental Controls
- Windows 7 Parental Controls Setup
- An FBI report about child Internet safety
- A number of Corporate Sites on Parental Controls: Parental Control Tools Education site, Use of parental controls on iPhone mobile deviceParental Controlled Browser and Social Network
- An Open Source project: mTime at SourceForge
- Information & Advice for Parents and Teachers: Threat overviews & Control software download links
- CNN,  How to protect your child from online bullies, by Doug Gross, 10/06
- Baltimore Sun,  New tools to monitor bullying, predators on Facebook
- USA Today,  Monitoring tool helps parents stop Facebook bullies and predators