[sgift]

5/6 sounds interesting to me. On the one hand Nintendo is the IP holder of the original ROM, so they would be the only ones allowed to legally download it if I understand it correctly. On the other hand the ROM was modified and contains a header which was made by someone else. So, to that part they don't hold the rights to download it? Or is it okay, because it's a derivative of their work?

[thristian]

No, Nintendo probably didn't download ROMs from the internet:

https://news.ycombinator.com/item?id=22756156

[dehrmann]

You might be able to argue the header was implicitly licensed because the author knowingly distributed it.

[yjftsjthsd-h]

Not at all. For instance, if I publish code on github without a license, it remains proprietary / all rights reserved.