I believe it depends on the original tone of the OP.
For example:
Someone who is making a password lock may ask about hacking to find vulnerabilities in their code. This is acceptable in my opinion.
Someone asking how to do hacking without any context, well, I'm of the opinion that, that's suspicious at best or just straight up malicious.
I'm assuming you are mainly referring to this post:
http://www.computercraft.info/forums2/index.php?/topic/28825-cc-ducky/This bit sounds innocent enough, it didn't flag as malicious until I read the rest of the post. I can still see this as a novelty, non-malicious utility but understanding the intent makes me ignore that.
I know you can't really emulate a keyboard with a floppy disk but..would be an interesting idea. There's no real need for it (just create a startup program on floppy and restart the PC..) but it would be an interesting idea to play around with nonetheless, especially if you can get it to inject keystrokes live, without having to reboot.
The rest of the post is the problem.
But what if you wanted to constantly spam a program with passwords on it's login screen without actually being at the PC, or something like that?
This is hacking, which is malicious, except for password recovery (I forgot my password/someone hacked me and changed it).
I've identified two issues here.
It would require a receiver program that catches floppy events and possibly others, hidden underneath the normal startup (floppy 'startup' gets run which runs the computer 'startup' above itself). However I still don't know of a way of injecting characters into a read function, and as far as I know it can't be done.
Hidden, usually, programs don't need to hide things, this is a trigger word. There can be false positives, such as hiding passwords when typing them in.
Injecting, also a trigger word, injecting in code typically implies modifying the program, this can be malicious (injecting a key stroke listener) or something the user intends to improve the program (modding games sometimes uses code injection to get the mod to run).
Can anyone disprove that it can't be done?
As BombBloke said in the thread,
Translation: "Can someone please write my cracking tool for me?". It's possible that you intended so an academic study style of view on this, however, what BombBloke has said is the more probable on the internet.