This guy is clearly snooping the downvoters as an instance admin and retaliating against them. Wouldn’t even have noticed if I didn’t stumble onto the modlog in Voyager by accident.
I might be of course wrong in my assumption. But I don’t remember ever interacting with anyone from that instance, I’m not subscribed to those communities and the dates correlate.
I can understand wanting to get rid of bad actors by any metric, including downvoting/upvoting patterns, which can sometimes be the only metric to identify trolls and bad actors who otherwise keep their mouths shut. Though here it seems a bit excessive.
The biggest issue is that downvotes or upvotes don’t say anything about the intent, so while I can accept someone using them as a metric to find a troll, you need to find other information or a pattern of abuse, such as someone downvoting everything in the community, downvoting with multiple accounts (persistently, sometimes mistakes happen), or repeated voting of specific topics.
It’s a lot more work to find out if someone is actually bad-faith downvoting and in most cases it’s just not worth it, and will come with a lot of false positives. Best to only do it for people repeatedly downvoting a user, or mass downvoting a whole community.