Turns out the model had ingested a pay-to-read article that cost upwards of $2000 [0] and was quoting the figures in it and referencing it directly (i.e. attributing the info to the article in question).
I knew about the paper but had never purchased it. I was actually surprised I could access the data through ChatGPT.
A few days later the same information was gone. I assumed someone might have decided to keep it on the low regarding having ingested all of these sources of restricted access content. I now get a generic blurb about the same question.
The opacity of it all made me a little worried. What similar models exist, trained on actually private information, for more nefarious purposes?
[0] https://www.marketresearch.com/Infiniti-Research-Limited-v26...