No, we'd only mark a story a [dupe] if it got significant attention in a different thread. I haven't heard back yet, but the most likely explanation is that a moderator (correctly) thought that one Tank Man story on the HN front page was enough.
Edit: oh - I think that one was actually marked a [dupe] by software. I'd need to double check this, but if so, it's because it interpreted the link to the other thread as a signal of dupiness.
Edit 2: yes, that's what happened. When a submission is heavily flagged and there is a single comment pointing to a different HN thread, the software interprets that as a strong signal of dupiness and puts dupe on the submission. It actually works super well most of the time. In this case it backfired because the comment was arguing the opposite.
> That's not quite accurate, but even if it were, there are easy ways to improve that bit of software if people start abusing it.
How easy it would be for bad actors brigading with freshly created accounts, or not-so-freshly created accounts with a history of brigading, to abuse this feature to censor stories?
I think I already answered this but I'll put it a different way: (1) not as easy as it sounds; (2) it would be easy to tell that they were doing it; (3) if they do it, we'll improve the software so they can't; (4) if that doesn't work, it's a minor feature and we can easily drop it.
