I think that by 1996 this was no longer the case. However, people that were used to being able to forward displays would commonly use "xhost +" (likely in .pro

I think that by 1996 this was no longer the case. However, people that were used to being able to forward displays would commonly use "xhost +" (likely in .profile or similar) to disable these access restrictions. That also meant you could do things like: DISPLAY=otherhost:0.0 xwd -root - | xwud - to take a picture of someone else's screen and display it on your own. I may have the syntax a bit wrong - it's been a couple decades. ;)