Parental controls

Parental controls are features which may be included in digital television services, computer and video games, mobile devices and software. Parental controls fall into roughly four categories: content filters, which limit access to age inappropriate 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. Another feature of parental controls is the ability to blocking rating, such as Parental Advisory, TV-MA for TV, R and NC-17 for MPAA, and M and AO for ESRB.

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 and 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 unauthorized 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.

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