Spent many (un)happy hours in front of both SGI Indy and SGI O2 during my PhD...
High point was definitely when we found out that if you telnetted to another box you could remotely play audio clips and the operator typically had no idea what was going on. Every single device ended up with a collection of Star Wars audio clips ... :)
Ahh... the required "guest" account with no password on it.
In SGI tech support (East team '96, Unix team '97 - my Indigo was dewi.csd.sgi.com), it was the way we copied files around (the Troops had just come out) and also had a internal tool that would pop up a window on someone else's machine to get their attention (if they weren't directly paying attention to the multicast chat program...)
I remember SGIs having incredibly poor security, at least with IRIX 5.x. Authentication for X11 was totally non-existent in the default configuration. If someone was logged in from the console, you could pop windows up on their screen (and sniff the keyboard) from remote.
> Ahh... the required "guest" account with no password on it.
That plus the lack of a default /etc/shadow, because reasons, made for fun times. ;-)
Something similar was possible with a PDP and teletypes at undergrad in the 70s. We had great fun sending (what looked like) operator messages to users telling them to log off or their teletype would BLOW UP.
And if you were teenage college students way more risque clips than Star Wars :-) One of my fondest memory is when a sophomore buddy of mine does a telnet and sets the display to local ip and starts clicking on random audio files. The operator on the other side is a freshman. Comes running to the other room sees my bud and being one year senior asks - dude that SGI is making weird noises. Realizing what has happened my buddy quips - ah it makes those noises when it is heavily loaded :-D
Another issue some SGI (O2) had: they didn't clear the entire video/memory buffer between logins. So, occasionally, when you logged in on the console, you'd see random images from the previous user on the screen. Apparently the user before me was frequently surfing porn :(. After that the group lead updated the MOTD to explicitly say that was not allowed.
you could do this on macs too with the "say" command. Back in late 2000s we were utilizing the xcode method of pooling developer workstations together to increase build speed. This meant most of us just shared creds and allowed colleagues to shell-in or remote-in to change settings etc. I am sometimes guilty of shelling in and running say "i can't do that dave" or something to random unsuspecting colleages.