Hi,
as everybody probably knows here, userboxes made vote-stacking und campaigning easy, since one can easily find the "right" people to vote on a subject.
Maybe a technical solution to this problem is possible. What if a bot substitutes all userboxes on the user-pages? Maybe it's even possible to somehow "tag" a template, so it is always substituted? This could be used on warning templates as well.
Of course this wouldn't eliminate vote-stacking at all, since one can still find the "right" people on various Wikiproject pages, but IMHO it's still a step in the right direction.
best regards