By Fabien Loudet, Senior SysOps at Rosetta Stone
Debian based distributions offers a package named molly-guard. It is a utility preventing yourself to accidentally reboot or shutdown the wrong system.
Once installed, it will override the existing shutdown, reboot, halt and poweroff commands by asking you to type the hostname of the machine, in order to confirm that it is really what you intended to do.
$ sudo reboot
W: molly-guard: SSH session detected!
Please type in hostname of the machine to reboot: ^C
Good thing I asked; I won't reboot tianhe-2 ...
W: aborting reboot due to 30-query-hostname exiting with code 1.