2 Instances are being used for coordinated vote manipulation, and should be defederated. chinese.lol lemmy.doesnotexist.club
The attacker seems to be the admin of those two instances. Both instances have their registrations closed.
Edit: It is now open for both of them, or was already. I checked the Fediseer page for both instances and it still says that their registrations are closed.
Though it is suspicious that no captcha, email confirmation or manual approval is required for both of these instances. The admin of lemmy.doesnotexist.club seems to be inactive since their account creation yet this instance is still running. If the admin is the attacker, it could also be that they are the one behind the recent nicole spam.
A individual user airing their personal biases and manipulating lemmy isn't good for the community, regardless of how you feel about their target. This is a really bad thing (tm)
The attacker seems to be the admin of those two instances. Both instances have their registrations closed.
The alternative theory would be that these instances had open registrations, but rightly closed registration down after the admins noticed the bots. chinese.lol is on 0.18.4 with an admin with a 2 year old account, lemmy.doesnotexist.club has an admin with a 1 year account, and it was also that instance that the 'nicole' person has used before. This downvote attack would need to be a long time in the planning for what you're suggesting to be true.
Upon inspecting the actual websites, the registrations seem to be actually open for both instances with no email confirmation, captcha or manual approval as one user pointed out. I checked the Fediseer page for these instances. What is the update delay for Fediseer?
I don't know. It's not something I'm familiar with - it might just default to saying 'closed' if it doesn't have the data.
It's interesting that the obvious bot accounts on those instances were set up in mid-March last year, so I'm guessing that these are somebody's army that they've used before, but overplayed their hand when they turned it on the DonaldJMusk person. The admins can reasonably be blamed for setting up instances with open registrations and no protections and then forgetting about them, but I'd be wary of blaming them for being behind the attack directly. The 'nicole' person is unlikely to have used their own instance - it's probably just someone with the same MO as whoever owns the bots, finding and exploiting vulnerable instances.
People forget about subscriptions all the time when they are cheap enough. The admin might even have some kind of grouped payment for multiple domains/sites and doesn't bother cleaning them out to shut them down.