> echo "Oi you! Log off!" | wall
>
I'd do something more evil like :
init 1
or
touch /etc/nologin
or
ps aux | grep -v [r]oot | grep [p]ts | awk '{print $2}' | kill -9
I think the last one would work, but it might also kill other things.
Perhaps looking for bash processes would be superior.
*yawn* *stretch* *sleepy*
David.