I used to be active on one of my country’s most popular forums, if ranked by daily visits. Self-help Q&A style. Apart from me, there were pretty much only three users contributing about 90% of the content. One of them being the only mod. It took me years to figure out, from the timing and the writing style of the posts, that this mod also poses nearly all of the questions and gives all of the first answers too, using a new single-use sock puppet each time.
At the start of this year, it devolved into plain attention whoring and it was really sad, so I left.
We get them a lot around here. They don’t make for good pets, but they keep the borogoves at bay.