I get that this is not a technical thing, but neither was the highly-discussed article on drug legalization:
https://news.ycombinator.com/item?id=11330587
I believe there was a thread on the U.S. and Paris attacks. Is there a reason that there isn't one on this attack?
Thus, lots of users are probably flagging these articles as off-topic. Also, many, many duplicate articles about this have been submitted, so those are getting flagged as dupes.
[1] https://news.ycombinator.com/newsguidelines.html