“Emulators community” have a partucularly peculiar take on that by the way.
Current gen emulator developers usually say you should rip your own ROMs from the physical media instead of just downloading them from torrents (even if you have the disc/cartridge on hand). I don't think anybody's actually doing that, but discussing downloads is banned on official channels.
Not sure about other content, but for games (and other programs) in particular this isn't quite true in the US (Copyright Act -- Section 117). You're explicitly able to authorize another individual to do the ripping on your behalf, and they can transfer to you the result. Websites offering those for download are problematic because they usually don't verify ownership or take any steps to ensure copies are destroyed or transferred when the underlying media is transferred.
Also, IANAL, but I suspect the order of events might get somebody into hot water. Although the effect on the creator would be the same, I'm not sure it's legal to (1) make a backup, (2) be authorized to make a backup by a media owner, and (3) transfer it -- as opposed to (2,1,3). I.e., hosting the content perpetually might be illegal regardless of your access controls. That isn't a problem with upload/download/sharing per se, but it does potentially make doing so more complicated.
Current gen emulator developers usually say you should rip your own ROMs from the physical media instead of just downloading them from torrents (even if you have the disc/cartridge on hand). I don't think anybody's actually doing that, but discussing downloads is banned on official channels.