Their API TOS basically forbid it. Simple as that.
It's like distributing GPL code in a nonfree application. Even if you didn't "consent to [the original author's] ToS," you are still going to be bound to it via the redistributors license.
In the context of the GPL, are there real examples of judgements which bind defendants to a license they never saw or knew anything about, because of the errant actions of an intermediary?
It gives OpenAI a legal basis to launch a law suit if they want to.
Would it succeed? Is it right? Do they care? Eh.
…but, if I as some random reddit user say I might sue you for making a LLM you for training on data that may or may not have my posts in it, you can probably safely ignore me.
If you go and build a massive LLM using high quality data that couldn’t possibly come from anywhere other than openai, and they have a log of all the content that api key XXX generated; they both know and have a legal basis for litigation.
There’s a difference, even if you’re a third party (not the owner of the api key) or don’t care.
(And I’m not saying they would, or even they would win; but it’s sufficient cause for them to be able to make a case if they want to)
A lot of behavior that rides this line is rationalized via a careful cost-benefit analysis.
"I don't think they'll be bothered chasing after me"
vs.
"If it came to it I think the court will rule that they don't have a case after we play the pay-the-lawyers-all-the-money game"
vs.
"how screwed am I if they do, I lose and I have clearly, blatantly and provably violated their terms of service"
^
...because, and this is the point I'm making. There is no question; it is very very obvious if you do this, and it's not very difficult for them to prove it.
All they need is to slap you with a discovery order, look at your training data, and compare it to their output logs.
The internet is increasingly covered with OpenAI's outputs and they do not have grounds for a claim to prevent people from using them.
OpenAI can’t just start suing random people on the street without any legal basis. That’s how lawyers become not-lawyers.
There’s only a (somewhat dubiously enforceable) ToS contract between OpenAI and the user of OpenAI’s website. This is probably bullshit too - what legitimate interest does OpenAI have in a model output that doesn’t even belong to them, but it’s less obviously bullshit.