https://www.gally.net/miscellaneous/hn-em-dash-user-leaderbo...

So if EM-Dash is good proof of AI usage, and people who we can see didn't use AI / or predate AI being popular, are flagged, then that undercuts it by a lot.

>Top 50 users by number of posts containing em dashes (—) before November 30, 2022, when ChatGPT was released