Privacy

Privacy is the ability of an individual or group to keep their lives and personal affairs out of public view, or to control the flow of information about themselves. Privacy is sometimes related to anonymity although it is often most highly valued by people who are publicly known. Privacy can be seen as an aspect of security—one in which trade-offs between the interests of one group and another can become particularly clear.

The right against unsanctioned invasion of privacy by the government, corporations or individuals is part of many countries' laws, and in some cases, constitutions or privacy laws. Almost all countries have laws which in some way limit privacy, for example taxation normally requires passing on information about earnings. In some countries individual privacy may conflict with freedom of speech laws and some laws may require public disclosure of information which would be considered private in other countries and cultures.

Privacy may be voluntarily sacrificed, normally in exchange for perceived benefits, but often with little benefit and very often with specific dangers and losses. An example of voluntary sacrifice is entering a sweepstakes or competitions. A person gives personal details (often for advertising purposes) in order to have a chance of winning a prize. Another example is where information voluntarily shared is later stolen or misused such as in identity theft.

http://en.wikipedia.org/wiki/Privacy