I'm coming up with all sorts of similes but they all sound snarky, and I don't want to be snarky, so I'll just say it straight: there is no "integrity" in an online poll.
The results are always stunningly, catastrophically, inarguably invalid for any sort of rigorous use. The only thing that makes this particular poll more obviously flawed than the Ron Paul surges which were more obviously flawed then the garden variety online poll is that the latent vulnerability was exploited to an extent approaching parody.
(Note you don't have to have an adversary at all to make an online poll invalid. They're always the result of self-selection on the part of the participants anyhow.)
But you're right - in any case where the voters find you, your results will be trash.
I'm guessing some kind of statistical method for determining which votes don't fit the profile of a site's visitors combined with actively weeding out obvious instances of mass voting could make the results at least appear more accurate.
Sure there's no actual validity or rigor to online poll results, but the point is more to have results that at least appear plausible.