My suggestion is to issue each voter a card (like a MetroCard) that the voter must swipe at a kiosk when he enters or leaves the theatre. Then, either the online database, or probably more easily the card itself, would have a record of which shows the voter has seen. When the voter votes then the tabulators at Grant Thornton (the accounting firm with those ridiculous silver attache cases) can determine in which categories the voter is allowed to vote and only count those votes.
