[runako]

Correct -- it can identify one of your (current) voices, written with your knowledge that the text will be used for the purpose of having an LLM determine whether you wrote it. This is a mentalist setup.

Expanding on that...you are fully capable of writing e.g. product instructions, or marketing copy, or religious verse, or a poem, or a fictional quote from a fictional character in your upcoming novel. I would consider it unlikely that any LLM could identify you as the writer of any of those (though Claude might infer it was you given your chat history). The point is that Pangram claims to be able to do exactly that!

Pangram is also making the claim that they can, to a high degree of certainty, identify when someone else wrote text and claimed it to be yours. This, when Pangram has not ever seen a writing sample of either writer. This is quite obviously ridiculous!