In December 1980, I ran into a kid named Micah Hirschman, whose father happened to have an account with a company called Bloodstock Research, which used a RSTS/E system; I assume the company kept historical records on the bloodlines of racehorses for breeders and bettors. I used the Hirschman account to connect to Bloodstock Research so I could exploit a security flaw and gain access to a privileged account, then Micah and I played with the operating system to teach ourselves about it, basically for kicks.