If it's a particular community being targeted, I'd probably start with people who aren't subscribed or don't contribute but camp out downvoting everything anyway. I mean, to me it sounds very much like this user's community is being blatantly targeted, so I'm not sure I understand why trends still need to be researched before anything can be done about it.

But I'm not an admin and I actually don't know what tools you have available to you. I was just under the impression that you could see when people who don't actually belong to a certain community go there just to downvote everything. Reddit managed to make people fear consequences for downvote brigading though, not sure how they pulled it off.

If this really is something that admins on various Lemmy instances are just too helpless to do anything about, then I apologise for directing my anger towards admins. And then I don't know what the solution is either because without any sort of assistance in the matter, women are just going to give up even trying to set up spaces here (actually seems like that's already happened for the most part). And so the culture will just never change.