It otherwise could be said to not concern me, but there is one who has been banned before who keeps coming back in different incarnations for the sole purpose of targeting/smearing me (I should emphasize the word “smear” considering the admins from other places who saw the pointers saying it was smear but then right after saw the smear and thought “oh look, it’s trying to tell us something” like there’s not only an issue with due process but also focus).
Afaik there’s no built-in way to see the IP of a user.
Does the unbanned one cross any rule-based boundaries related to harassment or witch-hunting?
No. Just block the user.
They’re a mass-downvote troll too, if that counts for something. Not adding to the plea to do something about the person Leni is talking about, just saying as someone who has encountered them being difficult and confusing me as her.