Annoying other users in terminal!

some days ago someone asked me about annoying others with write command.
a simple way to do this is using the watch command :
watch "echo ha, ha, ha! | write USER"
in which USER stands for the victim's(!) user name.
for annoying all users you can write it this way:

watch " for i in `who | cut -f 1 -d ' ' | uniq`
do
echo ha, ha, ha! | write $i;
done
";
simple and obvious.
good luck!
and be nice!!

P.S.
an alternative is to use wall command