In my previous post I promised to explore some ways that we can maintain anonymity on the Web, even in light of the numerous ways personal data is mined everyday. The key piece of personally-identifiable information that we scatter across the web (frequently without any thought) is our IP addresses. Almost every time you visit a website, your IP address is logged - a digital record that you have been to that site, that you have requested to view its content. It's trivial, in most cases, to find out who your Internet service provider (Comcast, Verizon, Time Warner, Qwest, etc.) is with this IP address. Someone who wants to bring a tort case against you or a governmental agency interested in you for any reason can subpoena your ISP for your identity - recall the link in my last post about National Security Letters. Therefore, if you want to maintain some semblance of privacy as you browse the Web, you cannot be leaving y0ur IP address at every site you visit.
One solution to obscuring your IP is using a web proxy, like Tor. When you use a proxy, all of your Web traffic passes through the proxy - that is, the proxy is the only server you connect to. Then, the proxy connects to any site you wish to visit on your behalf. Thus, if you were using a proxy and if all visitors to this blog were subpoenaed, your IP would not be there - just the IP of the proxy, who likely keeps no logs, and thus could not comply with a subpoena.
Tor is a good, free proxy service. The technology was originally developed by the U.S. Navy, and it is more complex than your average proxy. Tor bounces your Internet traffic to multiple relays all around the globe before connecting to your intended destination. You can learn about the Tor Network and the values it stands for here. To get started using Tor, you'll have to install a Tor client. I use a Mac, so I installed Vidalia.
Once you've got a Tor client installed, you can use it to connect to the Tor network. This is only half of what you need: you'll need to tell any programs - Web, torrent, IM, etc. - that you want to anonymize to use Tor. For Firefox, it's easy. Just install the Tor add-on. The nice thing about about it is that you can enable and disable Tor on the fly - you wouldn't want to keep Tor on all the time because it is very slow.
I just installed Tor recently to see what it's about. I notice that it has a few downsides:
1) it's very slow
2) many web pages detect your location (using your IP) and render the page differently depending on where you are coming from. While using Tor, web sites will detect your location as the location of your Tor proxy. Therefore, I noticed that several web pages were displaying themselves to me in German. (This goes to show how much information about you is used to determine your browsing experience.)
3) I read that some employers may not appreciate your use of Tor at work.
Anyway, for me, at least, the hassle of using Tor outweighs any benefits it serves. I like the ideology of Tor more than I actually find it useful to me. :)
Of course, I would be remiss not to note that there are certainly downsides to the proxy methodology: like many good ideas, it can be abused by those who seek to perform nefarious actions under the cloak of anonymity.