When I was in college, our email was on a Unix server. We would login via serial connection or telnet over the network, and get a korn shell. The server was poorly secured. Everyone's login device was world writable. So people would just see who was online, see the username of someone they wanted to mess with, take note of the pts(network) or tty(serial) device their connection used, and cat ASCII penises to it.

cat animated_dong.txt > /dev/pts/4

It was a simpler time.