Edit: these are just gut-feeling numbers but we've had many dozens (perhaps hundreds) of email exchanges with users about this to date. Usually when we ask them if their post was genai, probably 90% say "oh yes, sorry, I didn't realize you had that rule". Of the other 10% or so, when we ask further, it usually turns out that they used some other tool (a grammar checker, a machine translation, some kind of toucher-upper, etc.) which left LLM imprints on their post. It's pretty rare for someone to insist that they wrote the text entirely by themselves with no LLM or similar tool. Of those, I'm sure some are false positives.

There have also been a few instances where I didn't fully believe them, mainly because they'd already posted other things that got classified as genai. Fortunately this is rare. The vast majority of users who we have this sort of conversation with are sincere, legit users who don't know much about HN. Our hope is therefore to convert them into informed community members!