Anonymous Web surfing allows a user to visit Web sites without allowing anyone to gather information about which sites the user visited. Services that provide anonymity disable pop-up windows and cookies and conceal the visitor's IP address. These services typically use a proxy server to process each HTTP request. When the user requests a Web page by clicking a hyperlink or typing a URL into their browser, the service retrieves and displays the information using its own server. The remote server (where the requested Web page resides) receives information about the anonymous Web surfing service in place of the user's information. Anonymous Web surfing is popular for two reasons: to protect the user's privacy and/or to bypass blocking applications that would prevent access to Web sites or parts of sites that the user wants to visit.
An anonymous surfing service can make a user feel more secure on the Internet, but it doesn't permit a site to often the visitor personalization. This means that the a site cannot tailor its content or advertising to suit the individual user. SafeWeb and the Anonymizer are the most commonly used such services. Lucent's Bell Labs created its own version, called Lucent Personalized Web Assistant (LPWA), as did the Naval Research Labs, whose project was called Onion Routing.