Yeah, the poll allows multiple votes. There is no option within the software to prevent it. Obviously I’d like to assume that most people will just vote once, and that even someone votes a dozen times, it’s not going to sway things in any major way. And I’d like to think that it’s just not worth the effort for someone to come up with some crazy auto-voting system to cast a billion votes.
I’m going to keep an eye on it. If I find it to be an issue, or suspect that voting is at all compromised (or, the general consensus of the audience is that they’d feel better knowing the polls were secure), I will just shell out for a poll service that allows votes to be restricted to IP.