bash TMOUT for emacs

[Dan Jacobson]

Gentlemen, at the gala festival I have left emacs running and
forgotten on a terminal that I can't even remember what room is in.
Well, if emacs had a timeout setting, like bash's TMOUT, then I
wouldn't need to worry that some perpetrator could molest my files.

       TMOUT  If  set  to a value greater than zero, the value is
              interpreted as the number of seconds  to  wait  for
              input  after issuing the primary prompt.  Bash ter-
              minates after waiting for that number of seconds if
              input does not arrive.