While considering the free proxy advantages and disadvantages we knowingly did not pay attention to the nominal division into legal and illegal proxies. The first adjective that comes to mind when speaking about "anonymizer" is "illegal", but it is not fully correct. We have examined functions and purposes of proxy servers and noted there are many non-criminal aims for using them. For example using proxy server can sometimes protect corporate information from internal and external intruders.
At the same time legal proxies are those that are used for "defensive" purposes. Their activity is legal in terms of current international and local legislation.
As the name implies illegal proxies are created and used to bypass the laws relating to both the Internet itself and the data transferring and the scope of copyright, cultural heritage, civil rights and freedoms of other users.
The best-known illegal proxies form proxy botnet. These proxy servers are virtual and are not located on the same physical server. They are splitted up on a large number of computers connected by means of specialized software to the unified network. Proxy botnets are usually being formed without computer owners’ permission and even without knowing about such an activity.
Proxy botnet in fact is the result of a virus that penetrates to the victim's computer and is then used to mask the IP address of the attacker. The main danger of botnets is that they are commonly used for further attacks on the servers of companies, institutions and organizations. At the same time it does not matter where the victim is located as well as the geographical core of a botnet (each of compromised computers is called "zombie"). The attacks can be performed from anywhere and their initiator could be on the other side of the globe.
It is noteworthy that botnets creation is sometimes initiated and controlled by governmental and intergovernmental organizations to counter terrorism, and therefore can sometimes be considered as legal at least under the specific legislation.