I used to be a Mac prankster. A long time ago, in an office far far away, I wrote an extension called “obnoxious” which had no icon, it got to a friend at UCLA who put it on Compuserve. Someone took it, renamed it to “Arggh” and added an icon. It then ended up in Stupid Mac Tricks volume 1. It would randomly scream every 3-5 minutes.
So I put it on a co-worker’s Mac, and it was screaming away. Was bugging me that it was not bugging him lol. So I went over and said “How’s it going?” and while I was there, the mac screamed. I said “What the hell was that?” he said “I don’t know, but it does it every now and then” and went back to work. Man was I bummed.