A few days ago, I saw a blog post with a very reasonable blog topic ("case studies"), along with a very reasonable comment thread. Very pleasant thread, much more enjoyable than most comment threads. However, the comments all were odd. They were appearing to be like high-school essays about a topic, and never really interacted with each other, only just lecturing and meandering on the topic. I quickly concluded that the blogger and the commenters were all robots (or human spammers...hard to tell really) that were only generating spam content to make the blog seem more active.
Today, I saw this type of blog post again...reasonable topic, reasonable commenters, but only token interaction between the commenters. Further research shows that the blogger/commenters are actually human and commenting on the blog was actually part of a a school assignment. So I was fairly relived by that. But...you never know what may happen next...
EDIT: I'm not angry by the robo-blog because it produced content that was enjoyable to read and better than most human-generated content. On the other hand, I'm not happy that the robot-blog exist, because if one of these blogs exists...more can come. The blog comments were from ~2012, so it's possible that spammers have long since abandoned the practice.
EDIT2: And just to be clear, I think the robo-blog's comments have been plagiarized from real high school papers. And since I hate plagiarism, that's another reason not to be happy by this blog.