At CSRI, I learned that there was a program called f**k[1].c.
I looked at the source code.
It contained all sorts of harmful actions that would, literally, break physical devices (such as printers, etc.).
All of the code was carefully commented out.
After some playing around, I typed
> f**k me.
My session ended abruptly.
[1] That word was very verbotten at the time.