Hack 21. Make Yourself Anonymous

Don't let anyone know that you're on the Web.

Here are some ways to reduce the amount of information that web sites and other onlookers find out about you.

2.12.1. Basic Web Surfing Strategies

If you want maximum privacy, follow all of these rules:

• Never fill in web forms that request names, addresses, credit card information, or any geographic or demographic information. Never fill in online questionnaires. Never join a singles site. Never buy anything.

• Never download any programs, demos, or novelty animations from the Internet.

• Never provide your email address. Never use your email address in bulletin boards, newsgroups, message boards, IRC, or anywhere else.

• Don't use Windows or Linux/Unix with automatic operating system updates turned on.

• Never use an Internet Service Provider (ISP) that supplies you with a fixed IP address; it should be a DHCP address that's different each time you use it.

If having a known IP address or a known IP subnet bothers you, consider using services such as Anonymizer (http://www.anonymizer.com) for maximum anonymity. Before using such services, you must first persuade yourself that they are an organization that will credibly protect your privacy. You are using them as a portal for all your activities, after all.

2.12.2. Firefox Changes to Support Anonymity

In addition to careful web surfing, here are some concrete changes you can make to Firefox:

• Turn off all cookie support by checking the box in the Privacy panel of the Options dialog box.

• Carefully examine the installation for each plug-in you use. Don't let the plug-in send personal information back to those who deliver plug-in content. Ideally, delete all plug-ins, except the default plug-in file, from the Firefox profile and the install areas. The default plug-in file is named npnul32.dll (Windows) or libnullplugin.so (Linux).

• Examine your configuration of Adobe Acrobat carefully. Don't let it connect to servers or send form data.

• Review the extensions you've chosen to install; uninstall any that might have server connectivity.

• Stop all secret network activity [Hack #13] .

Finally, you can fool web sites into thinking you're using another browser. If you do so, the content set by the sites might change and the page display might not be exactly what you expected. This preference changes the User Agent that identifies Firefox:

general.useragent.override     /* set to string */

A typical string for a Windows version of Firefox reads:

Mozilla/5.0 (Windows; U; WinXP; rv:1.7.3) Gecko/20040913 Firefox/0.10.1

For best results, leave the words Mozilla and Gecko intact. Here's the string for Internet Explorer 6.0 on Windows XP (you can masquerade as that browser if you have nothing better to do):

Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)