Private Browsing remembers cookies
I would just like to let you guys know that Firefox recently remembers cookies when you are in private browsing mode. Cookies are not displayed in the show cookies window and therefor cannot be managed (cleared by the user). This gives the user a false impression that the cookies are not stored. The cookies are "remembered" throughout the entire session (until Firefox is closed) and is therefor available to any website throughout the session.
Do yourself a favor and test it: [www.html-kit.com/tools/cookietester/]
The only way ive managed to get past it,
is by setting Firefox to "use custom settings for history" to only check "accept cookies from sites", "never" to "accept third-party cookies" and to "keep cookies until i close the browser" with an addon called "self destruct cookies" installed, which clears cookies per browsing tab as tabs are closed.
This clears the cookies of a tab once the tab is closed, while still allowing websites, that need cookies to function (like gmail), to work.
Hopes this helps