Websites could offer special (active) contents that will reveal your identity (or even harm your computer) even if it seems that you surf anonymously with JonDo. Examples for such contents are JavaScript, Java, Flash and Active Scripting. Generally, all types of dynamic web contents are dangerous, if they are executed on the web surfer's computer. Sometimes browsers offer comfortable options for blocking such content, sometimes the usage of additional programs is to be considered.
Moreover, the web browser itself sends some contents that may be used to identify you, or at least to create an exact profile from what you are doing on the net - the HTTP Headers. These include, for example, your browser type, your language, the referrer (which page you came from), Cookies and Webbugs.
The downside of prohibiting these contents is, that some web applications cannot be used any more. This includes chatrooms, flash menus and animations, online games, and generally all web 2.0 applications. Therefore, you will have to do the right choice for you: do you want to maximize short-timed fun, or do you really want to stay safe on the net?
In the following, you find descriptions and HowTos for the installation and configuration of your browser and additional software for activating the right data protection settings for you.
In order to manage your cookies in a reasonable way, consider using CookieCooker (currently Windows only, but will be integrated in JonDo in 2007, too).