Select your localized edition:

Close ×

More Ways to Connect

Discover one of our 28 local entrepreneurial communities »

Be the first to know as we launch in new countries and markets around the globe.

Interested in bringing MIT Technology Review to your local market?

MIT Technology ReviewMIT Technology Review - logo


Unsupported browser: Your browser does not meet modern web standards. See how it scores »

{ action.text }

To cover that possibility, Tor can be used in conjunction with a “filtering proxy” called Privoxy. Filtering proxies are servers that block or allow the transmission of information, depending on how they are configured by administrators. Privoxy, for example, hides the information your computer sends through HTTP. Privoxy can also manage cookies and block pop-ups and other ads, but the HTTP filtering is what keeps the user’s information private. Installing and using Tor and Privoxy, though, require a good deal of computer savvy – it’s tricky for the average user.

For occasional use – say to check out a web site blocked by your company’s firewall – you can use a standard proxy server (a filtering proxy is one type of proxy server). These are services or Web pages you can navigate to and enter a URL; the server will then send the request for the page under its own IP address and return the results to you. Many proxy servers exist, some commercial, such as, and some free, such as and (Ironically, one can easily search Google for “proxy server.”)

The best known proxy server is probably the free Anonymizer, although it’s a “single hop” server, which means there’s only one step between you and the target site – not as secure as Tor’s scheme. Another downside is that Anonymizer runs on a single server, owned by San Diego-based Anonymizer Inc., which can make secure browsing a slow process. The company also sells subscriptions to the service, which grants access with greater bandwidth.

The Java Anonymous Proxy is another proxy system that offers anonymous Web browsing. It also provides anonymity for other Internet services, such as e-mail and messaging; but it does so through a cascade of servers, where a single server picks the chain of other servers. Although data is encrypted, the first server knows the path the data will take – providing one point where users’ identities could be revealed.

All this can keep your identity private while browsing online; but there are still many ways nonexperts can expose themselves online: through insecure e-mails, spyware, file-sharing applications, and viruses. Users should ask themselves: What’s at stake when I browse, and how much care do I need to take to maintain my privacy? To paraphrase slightly a famous line: The price of anonymity is eternal vigilance.

Home page image courtesy of Brian Stauffer.

5 comments. Share your thoughts »

Tagged: Web

Reprints and Permissions | Send feedback to the editor

From the Archives


Introducing MIT Technology Review Insider.

Already a Magazine subscriber?

You're automatically an Insider. It's easy to activate or upgrade your account.

Activate Your Account

Become an Insider

It's the new way to subscribe. Get even more of the tech news, research, and discoveries you crave.

Sign Up

Learn More

Find out why MIT Technology Review Insider is for you and explore your options.

Show Me