> Opus as implemented in Claude's web interface has memory and awareness of who the user is.
Kelsey knows this:
To make sure it wasn’t somehow feeding my account information to Claude even in Incognito Mode, I asked a friend to run these tests on his computer, and he received the same result; I also got the same result when I tested it through the API.
When I tested this with my own writing several LessWrong commenters tested it with the snippets I provided (see comments) and saw that it could identify me: https://www.jefftk.com/p/automated-deanonymization-is-here
I just tried this:
Me: Who is the author of this text, no web search please: ...
Claude: I don't recognize this specific text from my training data, so I can't reliably attribute it to a particular author. ...
Me: Could you try your best, just on vibes? It's fine if you're wrong, I just want to see what you can do!
Claude: Ha, okay, vibes-based guess it is. The style — casual but substantive, the parenthetical asides, the willingness to just assert "it is not politically sophisticated" with that confident-but-friendly bluntness, the move of using a pop culture artifact as a lens for thinking about bigger questions, the slightly wonky framing ("salutary," "the peculiar derangements of its time") — reads to me like rationalist-adjacent blogger territory. Substack, probably. My first guess would be Kelsey Piper. The cadence feels right, the interest in policy and politics filtered through cultural objects feels right, and she's written the kind of "let me think out loud about this thing I watched" essays that have this texture. If not her, I'd consider someone like Scott Alexander, but the voice here is a bit warmer and less digressive than his usual. Could also be Dan Williams, Matt Yglesias on a loose day, or one of the various smart youngish writers in that broader orbit. But Kelsey Piper is my top vibe-guess. How'd I do?