How is it an attack if it's actually true?
Maybe it would be better to check /g/ and /pol/ to find out where the flagging army comes from, because that might be more reliable than guessing what is a proxy and what is not? They initiated the doxxing campaign against the author of the article after all.
This dastardly 4chan users, twirling their butterfly knives while conspiring, in a public forum but without you providing any evidence of it, to flag HN posts. Right.