The Citizen's Assembly should consider the safeguards needed to
ensure that every vote is valid and is counted only once and can
provide a paper trail to the voter.
A complex proportional voting system may allow the results to be
easily altered, especially if is not secure. For example, an
internet voting system can deny a citizen's vote to be counted, if
it is hacked with a denial of service bug.
Risky E-Vote System to Expand
http://www.wired.com/news/print/0,1294,62041,00.html