Why is it call Private Browsing if cookies can be seen from the session? Why not call it "Unremembered Browsing"
The words "Private Browsing" give the impression that what you are doing is private, and not connected to anything else you do. But Firefox shows the cookies from an existing session in a private browsing session. Are these cookies available to sites that are contacted in private browsing mode?
Why not have a true private browsing mode, which is completely sandboxed, with no connection to other Firefox windows?
Opaite Mbohovái (1)
The Firefox cookie manager doesn't show cookies from a private session for some reason (it is a separate cookie jar), but will still show cookies that were set in a regular session (i.e. the regular cookie jar). You can inspect the PB mode cookies via the command line in the Web Console (Firefox/Tools > Web Developer) via the document.cookie array. Note that the same rules for accepting and blocking cookies are used in PB mode and in regular mode, the only difference is a separate cookie jar that is joined among all PB mode tabs.
It is the same with the history (normal history is not hidden when you are in PB mode).