yes that's true. That was made to prevent people voting a few people 20 times for every single category.
However, now people are using different accounts to give in identical votes bypassing the rule, which is the main thing that we're dealing with. These identical votes come from the same IP addresses, leading to the conclusion that it's either the same person cheating, or family members. We won't allow one person cheating obviously, but family members are a bit of a gray area so we're deciding on that right now.