I thought that was just me. It has seemed like posts critical of government policy can disappear quickly, but I don't have a comprehensive feel for how posts move on HN so it was only ever a feeling.

How can we collect data on the mobility of posts?

I've wondered this on Facebook too. Post something about a robot I made and people love it. Post something about US weapons killing children in Yemen and no one reacts or comments.

How much of that is the fact that people just don't respond well to those things and how much of that is the algorithm hiding the post for some reason?

How can we monitor moderated sites like this? What are the metrics we could collect?