A tweaked version of Firefox that makes Web browsing anonymous has been released by a group of privacy-minded coders. Every few minutes, the Torpark browser causes a computer's IP address to appear to change. IP addresses are numeric identifier given to computers on the Internet. The number can be used along with other data to potentially track down a user, as many Web sites keep track of IP addresses.

Torpark's creators, a group of computer security gurus and privacy experts named Hactivismo, said they want to expand privacy rights on the Internet as new technologies increasingly collect online data. The browser is free to download here: http://torpark.nfshost.com. It is a modified version of Firefox Portable, an optimized version of the browser that can be run off a USB memory stick on a computer. The Torpark browser uses encryption to send data over The Onion Router (link: http://www.onion-router.net), a worldwide network of servers nicknamed "Tor" set up to transfer data to one another in a random, obscure fashion. Internet traffic, such as Web site requests, carries information on where it came from and where it is going. But that is muddled using Tor, which has been endorsed by the Electronic Frontier Foundation, and is hard to trace back to a source.

One minor downside is that surfing with Torpark is slower than with a typical browser over the same connection. Torpark's user interface appears similar to Firefox with a few changes. It shows the current IP address that would be seen by Web sites in the lower right hand corner, and features a special "Flush Tor" button to reset a new, random server connection.