The few times I emailed hn@ycombinator.com I didn't get any responses.
Anyway, I just wanted to see if others thought Hacker News was being astroturfed, I never said those are sure case of astroturfing.
For example this one: https://news.ycombinator.com/item?id=19419362
Ok looks like it might be, but then I have to check the comment history to make sure this user is legitimate, which look like he is legitimate. So I guess I have to check the comment history of every user that makes a link to a paid product... sounds like a pain that could be automated.
Also, like for the commenters weirdly supporting China, I think the comment history is made in such a way to disguise the nature of the account (otherwise it would be too easy to figure it out, basic spam gets killed very quickly on HN thankfully)
(edit: Looking at your history, your account is 4 years old with two comments in this thread and one comment 4 years ago, may be a highjacked account)