There is a thing called the answerback message: computer sends Ctrl-E (0x05, "ENQ"), and the terminal response with the pre-programmed answerback message.
Maybe the message is a shell command, like "rm -rf *" or "chmod a+rwx ."
You can program this message in the setup screen of the terminal. Maybe you can set up all the terminals in the computer center at night...
You can send Ctrl-E to a user with "write" or "wall"..
This answerback message is actually really old, exists even in mechanical ASR-33 teletypes:
https://en.wikipedia.org/wiki/Enquiry_character
It can also be triggered by the mysterious "here is" key on the ADM-3A.