Here's a bit of the history of moving from open votes to secret votes:
http://www.bbc.co.uk/news/uk-england-leeds-31630588
This article discusses what should happen to ballot slips after and election, compared to what actually happens, and describes the potential for de-anonymizing votes.
http://www.theguardian.com/notesandqueries/query/0,,-1051,00...
Here's a bit of the history of moving from open votes to secret votes:
http://www.bbc.co.uk/news/uk-england-leeds-31630588
This article discusses what should happen to ballot slips after and election, compared to what actually happens, and describes the potential for de-anonymizing votes.
http://www.theguardian.com/notesandqueries/query/0,,-1051,00...