I have noticed that when you vote on a poll at slashdot.org
you can vote twice from two different IP addresses while
being logged in as the same user. I'm not sure if this is a
bug or a feature but it seemed logical to me that you
should only be able to vote once per user.
Logged In: YES
user_id=288856
I don't really consider this a bug, but its probably
something that someone could fix someday.