Users with karma above a certain level get's a 'flag'-link under each submission or comment. If a sufficient number of users flag an item then that item gets 'flagged' and eventually possibly also marked as 'dead' and it drops out of view.

Users don't have to explain why they flag an entry, but to my understanding it is usually because such users think that the entry attracts 'low quality comments', like bashing a whole nation state on scant grounds which inevitably causes the discussion to go down in flames.

I can understand this, but at the same time find it a pity that people can't have sensible discussions about sensitive topics. I find this story is one of those that deserve a better destiny than to be stomped away.