An anonymizer or an anonymous proxy is a tool that attempts to make activity on the Internet untraceable. It is a proxy server computer that acts as an intermediary and privacy shield between a client computer and the rest of the Internet. It accesses the Internet on the user's behalf, protecting personal information by hiding the client computer's identifying information.
There are many purposes for using anonymizers. Anonymizers help minimize
risk. They can be used to expose human rights abuses without retribution, to
speak about a taboo without loss of reputation, to receive information within a
repressive regime, to prevent identity theft, or to protect search histories
from public disclosure.
However, anonymizers can also be used by individuals wishing to avoid the consequences of engaging in criminal, disruptive, or socially unacceptable behaviour online. For example much of the child pornography distributed through the internet is accessed through anonymizers. Also, they are used to bypass web technologies that limit online content access to a certain number of minutes or quantity of data.