It's a complicated issue that nobody really has a good answer to, but there are some points in forum history that led to the current state of affairs
1) a long time ago (2005?) skyewelse emailed pixel to ask if he could use CS assets on his site: the original response has since been lost but the gist was given as "I don't care what people do with CS" <a href='http://www.cavestory.org/forums/index.php?/topic/483-pixels-thoughts/page__st__20' class='bbc_url' title=''>cite</a>
2) Hackers and modders and other people who make a hobby of deconstructing games and executables have an overinflated ego by nature and particularly SP Gardebiter made quite a bit of a fuss over people stealing assets from mods <a href='http://www.cavestory.org/forums/index.php?/topic/815-using-peoples-spritesmusic-whatever/' class='bbc_url' title=''>cite</a>
3) Some friend of ralren's made a terrible mod that used mine as a base and stole a lot of other stuff from people's mods as some kind of troll to the forums. I originally didn't really care that much but community encouragement led to me denouncing the mod. <a href='http://www.cavestory.org/forums/index.php?/topic/2377-super-street-nitos-journey-4-ex-edition/page__hl__+super++nito' class='bbc_url' title=''>cite, not original thread bc that seems to have gone</a>
and that's generally the basis of precident for how things are today. It still happens strangely often and I guess it's because people are too stupid to figure out how to prep a regular exe for modding(?) but basically the original creator retains the right to have derivative works removed. It is their choice whether to exercise that right.
1) a long time ago (2005?) skyewelse emailed pixel to ask if he could use CS assets on his site: the original response has since been lost but the gist was given as "I don't care what people do with CS" <a href='http://www.cavestory.org/forums/index.php?/topic/483-pixels-thoughts/page__st__20' class='bbc_url' title=''>cite</a>
2) Hackers and modders and other people who make a hobby of deconstructing games and executables have an overinflated ego by nature and particularly SP Gardebiter made quite a bit of a fuss over people stealing assets from mods <a href='http://www.cavestory.org/forums/index.php?/topic/815-using-peoples-spritesmusic-whatever/' class='bbc_url' title=''>cite</a>
3) Some friend of ralren's made a terrible mod that used mine as a base and stole a lot of other stuff from people's mods as some kind of troll to the forums. I originally didn't really care that much but community encouragement led to me denouncing the mod. <a href='http://www.cavestory.org/forums/index.php?/topic/2377-super-street-nitos-journey-4-ex-edition/page__hl__+super++nito' class='bbc_url' title=''>cite, not original thread bc that seems to have gone</a>
and that's generally the basis of precident for how things are today. It still happens strangely often and I guess it's because people are too stupid to figure out how to prep a regular exe for modding(?) but basically the original creator retains the right to have derivative works removed. It is their choice whether to exercise that right.