There is also this paragraph in their licence that is smart marketing-wise:
> 3. If the Software (or any derivative works thereof) is used for any of the Licensee's commercial products or services that have more than 100 million monthly active users, or more than 20 million US dollars (or equivalent in other currencies) in monthly revenue, "Kimi K3" must be prominently displayed on the user interface of such product or service.
So the mere knowing of it led them to lose it and Napster died because of that but also the actual nail in the coffin was that they couldn't significantly do anything to the problem about that given its P2P nature, Ipods were around the same time and RIAA was a bit afraid of that too but Steve jobs assured them that because of the walled garden they could better control the piracy issue and have proper ways of countering it.
Now aside from the interesting details of that time I showed, coming to my main point, Lawsuits can sometimes happen for lesser reasons than or just limited to plain and simple license violations and if a company is earning 20 Million dollars supposing so, then they might also have a really good lawyer insurance package and could lawyer up just as well.
The core argument lies on proving if AI weights are copyrightable or not from my understanding because the licenses could be best applied under copyright material not public domain materials and the other discussion[0] by @cosmojg shows the most likely cases of AI not being copyrightable?, so you would have to prove if AI is copyrightable or not.
Now that would be a fun lawsuit to watch though.
If you want to assess the position of the U.S. Copyright Office for yourself, the relevant text can be found in the Compendium of U.S. Copyright Office Practices § 313.2, "Works That Lack Human Authorship"[2], which states:
> […] the Copyright Act protects “original works of authorship.” 17 U.S.C. § 102(a) (emphasis added). To qualify as a work of “authorship” a work must be created by a human being. See Burrow-Giles Lithographic Co., 111 U.S. at 58. Works that do not satisfy this requirement are not copyrightable.
> […] the Office will not register works produced by a machine or mere mechanical process that operates randomly or automatically without any creative input or intervention from a human author. The crucial question is “whether the ‘work’ is basically one of human authorship, with the computer [or other device] merely being an assisting instrument, or whether the traditional elements of authorship in the work (literary, artistic, or musical expression or elements of selection, arrangement, etc.) were actually conceived and executed not by man but by a machine.” U.S. COPYRIGHT OFFICE, REPORT TO THE LIBRARIAN OF CONGRESS BY THE REGISTER OF COPYRIGHTS 5 (1965).
Oh, and there's also a bit in the following Section 313.3, "Works That Do Not Constitute Copyrightable Subject Matter"[2], which explicitly excludes mathematical principles, formulas, algorithms, and equations, along with DNA sequences and other genetic or chemical compounds, regardless of whether they are produced by humans or by nature. If one takes the perspective that machine learning models are algorithms, the conclusions on copyrightability are pretty clear.
[1] https://media.cadc.uscourts.gov/opinions/docs/2025/03/23-523...
[2] https://www.copyright.gov/comp3/chap300/ch300-copyrightable-...
As such as they have mentioned in the argument, their argument is sound in terms of the level of human involvement in creation of the artifact.