Pedantry is so boring. In conversational parlance, stealing is often the meaning without paying for. So yes, pedantically, this would be unlicensed use of vs the removal of the original from the owner's possession. But what else do you want us to think when even the FBI pushed the copying is stealing bit with their logos at the head of DVDs/VHS tapes?
We know for a fact that some LLM developers made digital copies of lots of copyrightable material for the purpose of training a system to create [unattributed] derivative works which had licenses expressly forbidding ingesting the content into an information retrieval system for the purpose of creating derivative works [without attribution], and that derivative works were produced, some of them containing substantial portions of content recognisably identical to copyrighted material.
LLM providers are free to argue in and outside court that EULAs or software licences are not applicable to them or enforceable at all, or that their specific actions fell short of violations but it's far more prejudicial to wade into conversations to try to shut down any suggestion that it might be possible to do anything unlawful with an LLM.
> this would be unlicensed use
which is exactly what the parent poster is implying - the hoovering up of data off the internet may not be unlicensed use. After all, the information is not what's copyrighted, but the expression of it only.
By calling it stealing, it already presupposes the idea that such hoovering is unlawful, before it is made clear that it is unlawful. And it prejudices the "jury" so to speak - the language for which you call the subject can influence other people's perception.