Interesting story! I hope you share a link maybe?
Knew I forgot something.
First Suspicious Blog Post (topic was "Case Studies")
Second Suspicious Blog Post (topic was "Pierre Menard, Author of Don Quixote" and "Funes, the Memorious")
Well all the posters on the first one link to other similar blogs. My bet is that it was a college psych class where they were all required to do blogs, and were also required to comment on each other's blogs. But of course they had to cite research to add to the topic rather than just saying "cool blog yay" or arguing with other posters. The class exercise is to write a blog that contains academic citations, then other class members engage with your blog and add their own material, which also has academic citations.
If you click through the posters on the first blog, you can see the same thing, with the original blogger doing similar responses to their blogs. I'm guessing similar for the second one, too. This is all written for their college professor's benefit, which is why all these people dropped their blogs after that year. Doing blogs is basically College Student 101 these days. At my college you just say "doing blogs" when they ask you what you're up to, and they all get it, and go "I feel your pain" no matter what course they are in.
EDIT: And they are probably specified a word count, too, which is why all the comments are similar length. Let me check that. Taking literally ALL the text of the first blog (heading and all), the word count is
500 words exactly. Basically this person padded the blog until they had that exact amount. So it's written to spec for a class assignment minimum. The comments where they back-and-forth are all around a 200 word minimum. There was one person who wrote a short comment, but his blog doesn't have any of the back-and-forth stuff from the others. So that fairly nails it. They were given an assignment to write a 500 word blog, then they have to comment on a minimum number of each others blogs for 200 words.