I wish I could read the second link, but not interested in bypassing their income (and not interested enough to pay them :) ) I'd like to know their research.

I had to sign up with my address, and I have to prove my identity when I vote. That all seems perfectly reasonable to me. Even a low-tech ink mark used by some places seems perfectly fine. The law is full of tradeoffs, and I think proving you have voted only once and where you are allowed to vote is perfectly legitimate.