E-vote advocates still don't get it...

I've messed up a ballot twice and no one batted an eyelid. Admittedly, that was with a NSW senate ballot paper which was about a metre and a half long and had more than a hundred candidates on it . . .

Generally speaking, if you're doing something odd and the polling place workers think it's suspicious they'll just ask you what's going on. If your actions are against the law, they'll call you on it and depending on the offence they'll do something about it, but this is a vanishingly rare occurrence.

It's quite common for people to take one ballot from each party as a way to not show which party they voted for by which ballot they took. Also there are blank ballots on which you can write the name of the party by hand and that counts as a proper cast ballot.

When you come to a voting facility you are first greeted by one or several "floor officials" that checks your voting card to see that you went to the correct facility, they then hand you the number of envelopes needed for the election (one for each thing that you have to vote for).

Next you pick a number of ballots. The various ballots are out in public (that is one area which we have received international criticism for since it relies on people actively taking more than one ballot to keep the vote secret so this is changed in the next election): https://sv.wikipedia.org/wiki/Riksdagsval_i_Sverige#/medi... . The different colors define for what the vote is for (say for federal, state-level and city-level).

Then behind screens you put said ballots into envelopes (one per color) and then you seal the envelope: https://lekeberg.se/images/18.37088d971653e4515769af1b/15... . Behind these screens people often leave behind the ballots that they never used which means that you often have free access to other ballots without having to take more than one from the public ballot place (which is also why the economic scale of vote buying goes out the window).

Next the sealed envelopes, your vote card and your national id have to be presented to the panel of vote officials: https://www.varldenidag.se/_internal/cimg!0/3u3yv7clzc8zr... who then first check that the vote card matches your national id, that you are in the correct facility and that the color of each ballot matches the envelope (there is a small open portion of each envelope to show just the lines that you can see in this picture of a ballot https://sv.wikipedia.org/wiki/Riksdagsval_i_Sverige#/medi... ) and that there are only one ballot in each envelope. This procedure is checked individually be each of the 3 officials (who all works for different parties) before the last official drops the envelopes into the ballot box.

When the election the cast ballots are calculated one by one bye each of the 3 officials individually (so there are always 3 tallies) which can be observed by any one willing to do so. At the end the 3 tallies are compared and if they differ then a recount is performed. Then the ballots are put back into the boxes, the boxes are sealed and officials from the "voting ministry" collects the boxes and transport them all to a single secure location where they then perform a more thorough calculation that takes weeks to complete, this last step is to verify that the first tallies where done correctly.

All in all the complete system makes vote buying or vote forcing so unreliable that it's unfeasible to conduct.