Using FF57. If you have the tabs set to "remember tabs from prior session on startup", you can still access password-protected sites. Scenario: you access your banking website, log in with userid and password. If you close down Firefox with the "remember tabs" set on, you will still be able to access the banking website: 1) if you log out of the banking website and close down Firefox, when you go back in to Firefox you are taken to the "logged out" screen, but you can still scroll back and Firefox will take you to the banking site still logged in; 2) if you don't log out of the banking website and you close down Firefox, when you go back into Firefox, the banking website is still logged in ... full access to the secure site. MAJOR SECURITY FLAW!! I have stopped using FF57 until this is fixed.