We already have a screen locker

wiki/src/blueprint/screen_locker.mdwn

-[[!meta title="Screen locker"]]
-
-The screen of a Tails session can be locked through the system menu, or by invoking the tails-screen-locker script directly.
-
-The ticket that tracked this work was [[!tails_ticket 5684]].
-
-This is useful for example for
-journalists that want to be able to leave their computer unattended in
-their office to go to the toilets for a minute and have their screen
-locked.
-
-[[!toc]]
-
-How do other live distributions do that?
-========================================
-
-  - [Knoppix](http://www.knoppix.org/)
-    - No password whatsoever → not possible to lock (or unlock!)
-    - http://www.linux-magazine.com/Online/Features/Getting-Started-with-Knoppix-7.3
-    - Base: Debian
-    - Desktop: KDE
-    - Might be interested in our solution.
-  - [Grml](http://grml.org/)
-    - Already have a custom script called
-      [grml-lock](https://github.com/grml/grml-scripts/blob/master/usr_bin/grml-lock)
-      which is a wrapper around vlock that asks for a password on first use.
-    - Base: Debian
-    - Desktop: fluxbox
-  - [Jondo Live](https://anonymous-proxy-servers.net/en/jondo-live-cd.html)
-    - Ask for user password on boot, then I didn't find a way of locking the
-      screen xlock. No xlock.
-    - Base: Debian
-    - Desktop: XFCE
-  - [Kali](http://www.kali.org/)
-    - Lock screen through GNOME and the default 'toor' password.
-    - Base: Debian
-    - Desktop: GNOME
-    - Low interest in our solution as Kali is not mainly used in live environment.
-  - [Tanglu](http://www.tanglu.org/)
-    - Lock screen through GNOME and the default 'live' password.
-    - Base: Debian
-    - Desktop: GNOME
-  - [Debian Live](https://www.debian.org/devel/debian-live/)
-    - Lock screen through GNOME and the default 'live' password.
-    - Base: Debian
-    - Desktop: GNOME
-
-Which password to use?
-======================
-
-It is already possible to set an administration password from Tails
-Greeter, and we could reuse it for unlocking the screen. But we also
-need a solution for when no administration password has been set.
-
-During the [[201412 monthly meeting|contribute/meetings/201412/]] we
-proposed to prompt for a password before locking the screen for the
-first time, if there is no administration password.
-
-How to activate it?
-===================
-
-  - Through the better power off button (#5322).
-  - Through the usual GNOME shortcut: Meta+L
-  - If a password has been set already:
-    - Automatically after X minutes of idle.
-    - When closing the lid.
-
-Implementation
-==============
-
-An initial implementation was started in [[!tails_gitweb_branch
-feature/better_power_off_button]], and reverted since it turned out to be more
-complicated than originally thought. This implementation and the problems
-listed below were discussed on the tails-dev ML in November 2012.
-
-Ideas to implement the password prompt before the first locking:
-
-  - Use a different PAM config for the screensaver
-  - Turn the admin password into the root one, and use the user
-    password's as the locker's one.