I agree that email validation is flawed in terms of ensuring uniqueness, so this is something I may drop and insist users create an account. One thing I have considered in the mean time is allowing registered users to hide non-signed in participants.
That'd be better. Make the default action when voting "vote as anonymous, unless logged in", and upgrade that anonymous vote to a registered one if the user decides to register after voting.
Also, having an account is not ensuring uniqueness either.
