I often use one (or several) Private Window(s) in Firefox since I hate ads. Some of my private windows have >100 tabs. However, when the system crashes, or there is a power outage, I lose all open URLs. So here is what I propose: When I open a new private window, I want Firefox to ask me whether it should save the open links. This should be to a file ONLY accessible to me, not any web site; and to itself, if I permit so. It should allow me to name this file (such as “Travel”), and offer me to encrypt it with a password. It should update this file as I open and close tabs. When I open another private window, say, after a system restart, it should allow me to open this file and have Firefox re-open all the pages.