If you post a comment on hackernews, you're already in the top 5% of people who visit hackernews. If you attain enough karma to actually downvote other people, you will probably be in the top 1%.
I have no idea what percentile I am in... I am absolutely sure someone is tracking/ranking it, because if I were actually training and AI, I would absolutely start at this large collection of bainiacs - but first I would ask permission, which I would guess would be politely declined.
The article itself is fairly mind blowing.
Down vote comment. Nope, only 1 arrow for up, and I am good with that.
Just refreshed, and now I can down vote some comments...
Refresh again... I cannot down vote posts, but can down vote even less comments... someone is watching, and laughing at this. :P
You cannot downvote direct replies to your own comments though if that helps understanding what might be happening here.
You can't downvote replies to your comments and in other circumstances I think.
I recently got to 300 and I saw no change in the UI.