i.e. all of them. Having last weekend voted in the election for the chancellorship of Cambridge University, I was reminded yet again that the number of one's ballot paper is always recorded against one's name on the polling station list. Which means that one's vote could be identified and the name of the candidate for whom one voted thus ascertained.
I know -
that it would involve a lot of effort;
that there are legal safeguards against anyone's doing so {I am tired of being told so — and if so, what are the exceptions? & if none then what is the point anyhow?};
that ballot papers are required by law to be destroyed after a certain time.
But, nevertheless, I have never received a satisfactory answer to the question: