In 1989, as a CS undergrad at UW-Milwaukee, I had access to a graduate Unix lab. One afternoon, the grad students discovered they could scan the network for users who had accidentally left their .plan files world-writable. For the uninitiated, the finger command let you see who was logged in, and it displayed their local .plan file. Because default security permissions were incredibly relaxed back then, you could sometimes write directly to someone else's file. The grad students wrote a script to append a snarky message mocking the users' permissions: "I AM FAR MOR THAN AN IGNORANT MORON..." Later that night, the lab cleared out. Left to my own devices, curiosity got the better of me. I ran a similar scan to see if any open files were left. I found one, and the user’s login name immediately caught my eye: "beaver". The temptation was simply too great. I opened their file and wrote the only logical sentence:"If you are reading this, then you are fingering the beaver!" After literally falling out of my chair laughing, undergraduate guilt kicked in. I didn't want the poor guy publicly humiliated, so I immediately sent him an anonymous alert. Within minutes, he saw the warning, deleted the file, and the prank was over. Back then, "going viral" just meant a few thousand people on Usenet seeing it, but I still wonder what would have happened if I hadn't tipped him off!