I had this same question myself but didn't ask it because I figured if I know I'm not going to show anyone else besides myself and a couple other people, why even state it out loud? It's not like anyone who would be offended would know, not that they should be offended anyway, unless I passed it off as my own work to those mentioned couple, which I wouldn't, and rather act upon the opposite approach.
The problem isn't that we mind our work being used, it's that we mind when it's used elsewhere without us being asked - it's just courtesy. I like to know if someone's throwing around my transliterations or not (though in my case, I usually throw them up at a public hub of some kind so there's no confusion necessary), and hell, just to ask is the right thing to do.
Plenty of people ask me very nicely to use my artwork, my Winamp skins, translations, etc etc… and those I don't mind. And while I think for an instant I would be kind of flattered that someone was, uh, stealing my stuff over someone else's, it's still stealing :p
But, yeah - it's always nice to ask before you touch, with anything. Like ocean said, one of the bigger problems with this is us-people using Japanese art with their not-permission. I remember in the past I'd use stuff from sites I really liked w/o permission, and even though I was twelve and had no clue how to speak the language back in the day, I still feel pretty ick about it. So now I try to ask politely to use art for my own use; it's just the right thing ! (Prime example: if anyone's seen the Zoro skin I did for Winamp, I used one of the works at cheap cannon, and just a simple explanation of what I was doing got me a very happy go ahead in response =) )
That, and, if you steal, Santa's giving you a LUMP OF COAALLL.