There's been plenty of times that I catted a binary file and broke my terminal settings. Sometimes fixable by running `clear` (without being able to see what I'm typing), sometimes not.

And I know PuTTY has a setting for what string is returned in response to some control code, that iirc per standard can be set from some other code.

.

In general, in-band signaling allows for "fun" tricks.

.

+++