“There was a program on the computer ... where two people could “chat” to each other while on the computer, sharing information.
Woz ... hacked into the depths of the system and discovered a way to break in on other people’s electronic conversations.
So when Gordon French, for instance, was flaming about his new trick with the 8008 Chicken Hawk, his home terminal would inexplicably begin printing out these semiobscene Polish jokes, and he never did figure out that somewhere miles away Steve Wozniak was doubled up in laughter.”
―
Steven Levy,
Hackers, Heroes of the Computer Revolution. Chapters 1 and 2