Please don't post insinuations about astroturfing, shilling, brigading, foreign agents, and the like. It degrades discussion and is usually mistaken. If you're worried about abuse, email hn@ycombinator.com and we'll look at the data.
The problem with in-thread accusations isn't so much the lack of legitimacy but the deletrious effect on discussion quality, which is fragile at best:
On shilling generally: <https://hn.algolia.com/?sort=byDate&prefix=true&page=0&dateR...>
On HN's fragility: <https://news.ycombinator.com/item?id=23047709>