It must be some kind of identity that still exists on the ballots. It only needs the willingness of both parties to verify it one by one with hands.
The problem is, the officials are democrats, and they will use everything to block meaningful attempts to audit the ballots.
I heard Giuliani sai]d,[b the burden of proof is in the one who presents the "naked" ballot, so if nothing can prove the ballots to be legal, it can be discarded. What do you think about this statement?[/b]
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Where I live any ballot can be traced back to a human, and verified.
There is a sort of "data collection" computer at the polling locations, but the ballots are saved and could later be manually check.
I don't think anything like this is the case in the states that just sent millions of vote-by-mail ballots out.