The difference between premium accounts and pirated ones is that the pirated ones can create multiple account names while the premium ones are stuck with a singular name. If by any chance a pirated account player decides to create an account on his name and then a premium one with the same name decides to do the same, the premium account will not be able to join with the reason of the account name already having a password. My fix to this problem would be to let it be possible to create multiple register commands on the same account name with the only difference being the password. That way, any coincidence can be resolved. By entering the right password on the login command you will join the respective minecraft account under that specific password. If by any chance this would create a memory overload on the servers, we could just create a cap on the amount of passwords per account name.