Wolves no they don't look at the numbers but they are there if scrutiny is required. The ballot is 100% annonimous however you need to weigh up what you would lose by crossing a picket line against what you would lose by staying at home.
In my opinion no punishment is ever justified. Just because you are aware of it doesn't make it right. What if an employer said " if you're late for work I will execute you" would that then be ok?