I ended up messaging the admins at the 16 instances show in the attached image. I pointed out their wild user numbers, and referenced the lemmy.ninja post detailing how that instance scrubbed suspicious accounts from their user database.
6 admins responded. They had all noticed the odd accounts and either thought the numbers were wrong, or weren't sure how to purge the suspicious accounts without nuking their databases. In the end they managed to delete a combined total of about 338k dormant accounts from their instances. (One of the instances seems to have gone down since then.)
I never received a reply from the other 10 instance admins, though 8 of those 10 instances appear to be down (as of 27 July 2023). 2 instances are still up and unchanged.
Between the actively removed accounts and the downed instances, this represents a loss of 930,004 inactive Lemmy accounts!
You can see the drop in the graphs on The Federation. The total number of Lemmy accounts has been cut in half over the past 3 weeks, from a peak of 2.18M to today's 1.09M. The change is mostly from these 16 instances.
I have to admit, I did not expect such a large change when I started this! Hopefully this bodes well for Lemmy's future as a place where actual humans interact, rather than a cesspool of automated comments and upvote/downvote brigading.
That's all I have for now. Keep your stick on the ice; we're all in this together.
Dude wtf, there are relatively many fucking servers which have well over thousands of inactive users. I checked some and it seems the mods of them are just posting under 5 posts on some other servers and than creating some communities in their own server and then leave quietly. Thats too sus... It may be too much paranoiac to think that there is more going about those servers but I just cant stop thinking it is too absurd
This is a possibility, but I think a lurker wouldn't sign up to those servers, they are literally randomly named empty servers. They would prefer more known servers, or they may just look up which server to choose and eventually end up on registering to known server.