User blog comment:EmpyrealInvective/Regarding PotM (again)/@comment-26326346-20151120064229/@comment-24101790-20151120064832

We can't go about checking every users' IP address. Apart from the privacy violation, it's also a lot of work (currently 50+ votes after just a few days.)

Additionally there's no way to restrict a poll so only specific people can vote/comment on the forum.