[patall]

I am not sure how you vote but in my country, you could not pre-fill the ballot because you only get it at the voting booth. You have a voting registration that you bring to the booth, there you exchange it for the ballot which you fill out in a closed cabine and the pass right into an urn. (Which is basically like a voting machine, you only fill out your vote at the place you are voting). Honestly, not a very good reason for voting machines, only maybe against mail voting.