"...sending mail to known foreclosures, getting that mail back as undeliverable due to the addressee having moved due to the foreclosure, then using that returned mail as proof the person should be purged from the voter rolls

How can someone lose their vote because they aren't living in the same home they were living in when they were registered, because it's been foreclosed, or for any other reason? Surely once you're on the current register you're entitled to vote in that area, no matter where you are living by the time the election comes round?

That's how it works with us anyway.