The idea came into my mind when I felt the need of it.
1. When the password protected window goes out of focus and / or minimized when it regains focus it requires password to show the private window.
2. Thumbnail of the "Private window" shouldn't be visible when hovered on the taskbar icon of Firefox, it should show a blank tab.
3. This password protection feature can be turned on and off in the settings, which requires a password.
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