I have been asked by one of my customers to supply "Jonathan Scott" proof voting system (Don't ask, its really not worth it). Because the membership system is not based on the MEMBER_ID but another field they want to be able to reliably check who has voted in which polls.
Having looked at the database at the M_POLL field there is a string of numbers, how to the correspond to the Poll they belong to
I assumme thats how the site knows which polls a member has voted in...
They really need to verify the online voters so when it comes to an offline meeting that there is absolutely no chances of ballot stuffing.
The M_POLL field holds the topic ID of the poll they voted in.
The next update of the poll mod will store the votes in a new table, instead of a single field like it is done now. Both MEMBER_ID and TOPIC_ID of the poll they voted in will be stored in the new table. So maybe that will be helpful to you for what you are trying to do.
Unless you can't wait for the next update of the poll. Next update should be released for the 3.3.05 and the 3.4 version, in the next 2 - 3 weeks.
You can head over to my forum and subscribe to the Poll Mod topic in the MODS forum, so you can be notified when I post the new version. http://ww.dsilvera.com/forum/