Claude Opus can now identify an author from their writing

Link: I can never talk to an AI anonymously again, by Kelsey Piper in The ArgumentOn first read, I found this a little bit sobering:“But soon, the entire debate over internet anonymity will be as anachronistic as an iPod Touch. That’s because Claude Opus 4.7 is here, and last week, I discovered it could identify me from text I had never published, text from when I was in high school, text from genres I have never publicly written in. And if it can identify me, soon, it will be able to identify many of you.”Kelsey Piper plugged in 125 words from an unpublished essay and asked Opus 4.7 to identify the author. It listed her as the most likely answer.I was skeptical, so I did the same: a few paragraphs from an essay, which I plugged into an account that isn’t connected to me. Here’s what Claude said:“Based on the style, themes, and specific concerns in this snippet, my best guess is Ben Werdmüller.Several signals point this way: the framing of the open social web as a movement rather than…