Since the voting node checks the IP, if two users are accessing the net thru the same proxy - only one will be able to vote.

I suggest that for every loggedin user we can track the username to check whether he has voted or not, and if the user is not logged in then we can use the IP. Using the IP is still not a good idea as in a dial up line the IP changes everytime u dial in.

Better to use something else (But what?)