Our university lab had somehow enabled xhost+ or the equivalent
Because we could send the output of xview to other screens in the lab.
It was 1996 or 1997 and people didn't have internet in the dorms, so they couldn't enjoy pictures of pretty ladies they downloaded from the internet from the comfort of their own room, mostly. So they did it in the lab.
That usually didn't go unnoticed, but most didn't care.
A friend hat the idea to make a banner, a collage of a stop-sign and other icons found on the internet with the words "Stop. Internet-Police. You've been caught watching porn" - or something like that (I cannot remember exactly).
When we spotted somebody enjoying a set of naughty pics, we sent him the banner via xview.
They'd usually straighten-up (having been thrown out of their porn-trance abruptly and without warning), close all browser windows, log out and leave the lab immediately.
Biting the hand that feeds IT
