Looks like it was a “paywall bypass” for GPT-3.5/GPT-4 through vulnerable third parties. DMCA forbids access control circumvention, among other things, so seems like a takedown is expected.
But isn't DMCA about protecting copyrighted content? And the copyright to ChatGPT responses must belong to the one who have asked a question because ChatGPT is just a tool. Whoever is using the tool should own the copyright on replies.
IANAL, not even US Person, but 17 USC ss 1201 (a)(1)(A) states: "No person shall circumvent a technological measure that effectively controls access to a work protected under this title. ...".
Is "work" defined anywhere by law or by precedents? I just genuinely don't know. It seems to me that depending on that, the OpenAI API might be considered "work" just like a copyrighted manuscript. I'd also think there must be some other laws forbidding hacking, but DMCA must have a fast track everywhere.
But ChatGPT responses are not copyrighted and cannot be copyrighted by OpenAI. They are the work of whoever asked a question, so in this case the user bypasses the protection to create its own work, not to read someone's else work.
The model is proprietary and owned by OpenAI, therefore the outputs pf a proprietary process are at minimum copyrighted by OpenAI. When you sign up, you obtain a license to use that output as prescribed by the license.