i have a website with polls , i want the user to be able to vote one time only , i can’t use use his IP address to know that he had voted before as the IP address all system users using is one (they are on LAN with one WAN ip address) . using the cookies is good , but what if he deleted the cookies to vote again ? , i don’t want to use memberships also , or email verifications .
is there any way i could do it ? i don’t know maybe know his mac address somehow :p .
what javascript can offer me (information about his PC) ?
thanky ou guys .
How about an ever cookie? http://samy.pl/evercookie/