Some people could have multiple accounts appearing from the same ip if their are behind a router that is assigned just one ip by the isp and they are using NAT. IE if you have a fraternity house with 6 guys there and 3 post they will have the same ip if they are behind a router using NAT. It is not against the rules but if the ip banning tool is used too much and too swiftly it could hurt innocent people.
Just my two pennies.






