Where is the evidence it was removed by a moderator? I know that's the first thought, but HN doesn't have many moderators, and usually the moderators leave a co

Where is the evidence it was removed by a moderator? I know that's the first thought, but HN doesn't have many moderators, and usually the moderators leave a comment on a submission after taking a moderator action. I regularly come across a submission on the front page that looks interesting, read the article, then come back and notice it's been pushed to the 2nd or 3rd page. My assumption is that it was downvoted by a bunch of people, but it's still annoying. I wonder if there are any sites that track these movements?