We're a relatively small site. Though this thread is at the bigger end of what HN hosts, it's still manageable enough that when the two of us spend all day watching the thread and looking at the commenting, flagging and upvoting/downvoting, we can pick up evidence of manipulation and abuse quite easily. For example, we both independently noticed the user who was commenting/voting/flagging under multiple different usernames. It just looked weird. And it's easy to detect users who are driven by an ideological agenda from observing the patterns of their activity.
You have no idea how much we all value the effort you put into moderating HN!
It's one of the last bastions of large-scale intellectual discussion that hasn't be overrun by bots, teenagers, or trolls. Digg was destroyed, then Slashdot, and now Reddit is mostly AI spam.
Hacker News is a place where when I see spam, it looks obviously of place. And then an hour later... it's gone.
