Anonymous surfing allows you to wander the Internet without leaving any track of your computer's IP (Internet Protocol) address. This is accomplished via a proxy service.
When surfing the Web from the privacy of your living room, den or office, it may seem as if your movements online are completely anonymous. Unfortunately, the opposite is true. Everywhere you go you can be tracked through your IP address. The IP is a numerical value that maps back to your ISP (Internet Service Provider) and ultimately to your specific computer. It is linked to your computer by assignment to your login username and password.
When you request a website by clicking on a link or bookmark, your computer sends its IP address to the website along with the request for the page. The destination server answers by sending the requested page to your return address. Your computer receives the HTML data and the browser turns it into a graphic page you can view. In this way, websites can keep track of every page you view by logging your requests along with your IP.
Anonymous surfing defeats this ability by using a go-between proxy that 'stands' between the surfer's computer and the Web. This intermediate server, or proxy, handles all of your computers requests for you. Your requests go to the proxy, which relays them to the Web. The website sends the requested pages back to the proxy server, which then forwards them to your computer. Websites can only log the proxy's IP address, not yours. It's rather like having a valet run all of your errands for you, so that the valet's face is the only familiar face on the Web.
There are many free proxy programs for anonymous surfing, but most rely on using 'unwilling' proxy servers. These are private business servers configured incorrectly to leave open ports, which anonymous surfing programs can exploit. Enthusiasts use port scanners to check for unsecured networks, then post their addresses publicly on a daily basis. When administrators realize the breach, the port is normally closed. Therefore, using manual anonymous surfing programs means constantly preening the available list of proxy servers. Purists are willing to do this, because they believe it is the safest way to achieve anonymous surfing.
The alternative is to join a Web service that will provide a toolbar to use in place of the standard URL (Universal Resource Locator) in your browser. You can surf normally, using the toolbar address field to enter website addresses. The toolbar calls upon its own server to act as the proxy. Most sites that provide anonymous surfing of this type charge a monthly or yearly fee for the service, while others offer free trials.
Certain websites do offer free anonymous surfing, but the Internaut must surf from the website. Moreover, the proxy handles requests from paying clients before handling free proxy requests, which can make free anonymous surfing very slow.
Purists maintain that anonymous surfing through a website service is not very anonymous, as all of your requests and IP(s) are stored on their server. This could easily lend itself to profiling. Contrast this with using random networks around the world as proxy servers. The administrators have no interest in public Internet traffic per se. If they notice anonymous surfing, they will simply close the port. This actually keeps this type of anonymous surfing even more anonymous, because your computer's requests are not all located on one server.
Note that a proxy server is not considered anonymous unless it strips your IP address from its referrer value. This is a header that can point back to the IP of the requesting machine. In a true anonymous proxy, this referrer field will show the proxy's IP address, not yours. Free software programs like The Proxomitron can check proxies for anonymity.