Earlier quoted context omitted.
There are two different things when it comes to discussing training LLM's on "copyright" protected data, and I almost never see people differentiate. 1.) Training on copyright that is publicly available. You write a poem and publish it online for the world to read. That is your IP, no one else can take it an sell it, but they are free to read and be inspired by it. The legalitly of training on this is in the courts,…
I'm not sure there's any legal distinction though. Is a book publicly available? No, you have to purchase it. But once you do, you're legally allowed to let your friends and family and so forth read it too. As long as you don't sell copies of it (the "copy" part of "copyright"), or meaningfully take away the ability for the publisher to make money from sales (so you can't post it for the whole world to see on the int…
This means that it's not legal to download a rip of e.g. a CD that was uploaded without consent, even if you own a copy.
(This exception to the general right to make copies for private use was added in 2005 to make downloading illegal -- previously, only uploading was infringing.)
I would assume just the act of downloading this content was illegal in the relevant US jurisdictions as well.