Australia has a total hand count with machine verification (if they disagree the hand count is redone) and party observers.
Combined with mandatory voting I have total confidence in our system as one of the best in the world.
I don't believe it is an offence to vote informally but even if it was the anonyminity of the ballot woult make it impossible to enforce.
In the last Federal Election the overall informal vote share was about 5.92%. In some electorates it was above 10% [1].
The AEC doesn't distinguish between votes that were intentionally invalid and votes that were unintentionally invalid. I used to work as an electoral officer and in my experience the latter usually far outweighed the former. I saw very few if any ballots that were totally blank, about 10-15 where the person tried to make a statement of some sort and the rest were people who did not understand the instructions and number every box.
As far as I can tell, elections in Australia are seen as something you don't really ignore despite your individual disdain for politics.
[0] http://www.aec.gov.au/voting/informal_voting/
[1] http://www.aec.gov.au/voting/informal_voting/division.htm
TLDR: Greater direct democracy, we vote on everything.
Not any more.
Back when we all used actual real paper ballots, sure, but the new electronic voting machines don't allow for that.
cf. Black Mirror writer Charlie Brooker: https://twitter.com/charltonbrooker/status/74592155647647334...
What guarantees the vote cast matches the vote printed?
I've attended my jurisdiction's VAT (verification and accuracy tests). When the card or paper strip was unreadable, they just swapped parts until it worked. So the only thing verified was the printer was still working.
I accept the fact that someone has been elected, I don't trust that they were elected fairly.