Anonymizers are not completely safe. If a Anonymizer keeps records of incoming and outgoing connections and the Anonymizer is physically in a country where he undergoes a search warrant then there is a potential risk that government officials can reverse engineer and identify all users who use receives and how you use it. Most of anonymity state that does not keep records, but currently no way to confirm that. However, if the user used another anonymizer to connect to the Anonymizer exposed, the user remains anonymous. This is sometimes called daisy-chaining.
In addition, an unreliable network based Anonymizer is capable of man in the middle attacks. The Anonymizer can read, inject, and modify the content of the message that the user is sending and receiving. The Anonymizer can intercept and record private unencrypted information such as username and password credentials, credit card numbers, e-mails, etc., which have been transported using the Anonymizer. To avoid this, the content must be encrypted and credentials should be exchanged outside of the Anonymizer.
Because even Anonymizers trust, anonymity can not filter out any malicious code that may reveal the identity of the user who wishes to remain anonymous. See malware. Care must be taken to prevent information leaks. For example, the anonymity of an HTTP connection but not a DNS lookup can reveal the location of the viewer.
Anonymizers also present a high-value target. Groups opposed to people who want to remain anonymous target public anonymizers, especially as they are often misused.
freely available Anonymizers , open and above all HTTP proxies socks, usually operated against the owner’s knowledge of the server, botnetworks and other malicious programs are known to install the services. Are used to record passwords or place ads / malware in the (http / email) traffic and high damage to the owner of the server due to the large bandwidth consumed and the violation of security. “Bad” HTTP proxies, almost always anonymous connection to conceal the true identity of the client user to be more attractive, this can be detected through a free proxy analyzer