Why do you say it was censored and removed? It's dropped down to page two, but that's perfectly normal once something has been on the front page for a while.
It's only been 5 hours since it was posted, and the story has ~450 upvotes. In contrast, I see another story on the front page right now that was posted 18 hours ago and only has ~250 upvotes.
A big factor of the ranking algorithm is related to the number of comments; as the number increases, the ranking of the article goes down. This is intended to penalize controversial articles that may result in flame wars.
This article has <200 comments, while the other one has >400; this is likely a significant factor in the falling ranking, in addition to the age.
I also believe that upvote velocity is weighted more heavily than upvote quantity, but I could be wrong there.
The comment algorithm seems backwards. I hope HN at least does sentiment analysis to see if the flavor of the comments tends toward being negative before downgrading the post.
The HN mods routinely drop stories off the front page which they apparently deem overly political. I've seen many political stories instantly drop from the top 10 to page two.
