Basically, a proxy server is just an ordinary web server, albeit one with a special function. This server lies between the web user and the sites they are visiting; with requests for web pages and files being relayed via this server. This relay means that it is the servers IP address which is reported to the site being visited rather than the IP address of the web user. Why is this important? IP addresses, particularly static IP addresses, which are more and more common with the expansion of broadband service, can be used to identify specific users. Just think about the implications of that for a moment.
It should be noted that not all proxy servers will hide this information which can be used to uniquely identify you from the sites you visit – there are anonymous proxy servers as well; these provide a higher degree of anonymity to you on the web. However, how can you tell which proxies are really protecting your identity? Read on for a few tips on how to find safe web proxies.
First, you can use the “whois” command if you are running any variant of Unix or Linux on your computer. There are also web-based interfaces for this program available, including the ones available at domaintools.com which can tell you if the owner of the proxy has hidden their contact information or not.
You can also use Google or another search engine to look up the proxy and see if anyone has had any experiences of malfeasance with the proxy and what, if anything people are saying about it. Another good source of information is available from the homepage of the proxy server itself; there should be a terms and conditions of use policy posted on the site which will tell you exactly what the proxy does and does not report to other sites in terms of information about users.