[unsnap_biceps]

People with enough positive points have the ability to flag a comment or submission to indicate they don't feel like it belongs. Why it's flagged is sometimes difficult to figure out.

Here's the FAQ entry

https://news.ycombinator.com/newsfaq.html

What does [flagged] mean?

Users flagged the post as breaking the guidelines or otherwise not belonging on HN.

Moderators sometimes also add [flagged] (though not usually on submissions), and sometimes turn flags off when they are unfair.

[carlesfe]

Ah, I understand. I don't think it breaks any rule, so it must be off-topic.

A bit harsh maybe, but gotta agree to the rules to play the game :)

[_7acn]

In your article, you write that a social platform without trolls is impossible. You simply encountered a dumb-ass troll who didn't like the fact that you like Twitter and he reacted this way.

[unsnap_biceps]

If you look now, your submission isn't flagged anymore, people with enough points to flag can also 'vouch' and counter a flag, so it looks like enough people vouched to unplug your submission :) Sometimes it turns into a tug of war.