A discoverable non-banned account. Not from “ghost accounts”. If a server creates a massive amount of accounts to use them to vote, you can see that a small server has a disproportionate amount of registered accounts too, which probably will be otherwise inactive. Then you can reject votes from that server.
How would it prove that the account is real? I suspect that the meaning of “real account” is not the opposite of bot or sockpuppet.
A discoverable non-banned account. Not from “ghost accounts”. If a server creates a massive amount of accounts to use them to vote, you can see that a small server has a disproportionate amount of registered accounts too, which probably will be otherwise inactive. Then you can reject votes from that server.