> You receive each paper by the post before an election AND there is always all the papers in the voting place anyway.
That opens the possibility to observe people picking up the paper of $CONTROVERSIAL_CANDIDATE and dropping it into the box, thus revealing who they voted for.
Say hello to the butterfly ballot: https://www.asktog.com/columns/042ButterflyBallot.html
> You receive each paper by the post before an election AND there is always all the papers in the voting place anyway.
That opens the possibility to observe people picking up the paper of $CONTROVERSIAL_CANDIDATE and dropping it into the box, thus revealing who they voted for.