Ask HN: Are there voting rings on HN?

Lately, I've been noticing that content from a select few sites gets upvoted to the front page, and when I click the link and read the content I don't find anything that thought provoking or interesting. Usually, just a small observation about something.

Does this mean that there are voting rings that ensure these things get to the front page without having too much merit? Or do these authors have so many followers that even their mediocre writings make it to the front page? Or am I just "not getting it" and these are indeed very good pieces?