> and he gets modded down multiple times by the same user via proxy accounts.
"Modded down" means voted down?
How do you want to know about these sockpuppets?
I know a bunch of real people here who are rather critical about the monk you mentioned, me included. I doubt sockpuppets are needed.
Creating efficient sockpuppets which are not discovered by a database lookup is IMHO quite difficult.¹
I'd try to restrict the multiple upvotes to 10% of ones quota. Like this you'll need at least 20 votes (Chaplain) before being able to.
¹) and IIRC did the admins assure more than once that there is no trace in the DB for such a sockpuppet downvote farm.