Tons of people across the site lost reputation yesterday (UTC 7/23/23). I lost a measly 20 rep, but some people lost tons more. After losing 11k+ rep, poor Valorum's back down to 660k (oh, the ignominy!), and a lot of other users have seen similar plummets in their rep-score.
What's confusing me is why this vote-reversal has been attributed to 'Serial Voting Reversed'. Though I'm familiar with the general idea of what that means, I can't see how anything that's evidently affected so many users can be considered targeted voting. (In my experience, it's generally account deletion that results in such widespread repercussions.)
I realize that the specifics of voter fraud and when votes are thrown out are guarded information, but I do wonder whether a general picture of what happened could be provided.