Polls - very imp

I have noticed that I can vote any no. of times in any polls conducted on this site. Sometimes when I login in next time I can vote again. This problem is there since I joined the site. I never thought it to be a major problem. But it will be when voting for contests. Please take a look into that.

really? i never had that prob unless the creator of the poll chose for it to be a multi vote poll.................