There really is no way for the admin to determine if people have multiple accounts that are legitimate (i.e. family members in the same household) and people that have multiple accounts that are cheaters. Especially if the accounts were created from multiple IPs.
Not that I cheat or anything but I realized this when five of my friends played their characters using the laptop in my apartment, one after the other. All legitimate players, characters were all created with different IPs, could have all been made by myself since I visit all of these places where the characters were created.
Plus since I did legitamately refer all of them, I got referral credit.
//Just an observation
I only have one referral that comes over to play on occassion...
I told him to PM the admin if anything was suspected..so it's all good