Stack Exchange should be more proactive when a user continuously downvotes another user.
Example: I saw on https://travel.stackexchange.com/users/1810?tab=reputation:
This was triggered by the "Arthur's Pass" user"Arthur's Pass" (Wayback) user (Network Profile) leaving the website.
60 reps mean 30 downvotes on questions (this user mostly downvoted on questions). That represents ~10% of the questions posted by https://travel.stackexchange.com/users/1810. Furthermore "Arthur's Pass" user has only cast around 150 votes, which means that 20% of their downvotes were targeting https://travel.stackexchange.com/users/1810. It is ok to disagree but I believe there is a clear downvoting pattern here.
Why wasn't some serial/targeted downvote detection mechanism triggered?