I'll probably comment a bit here about the OP's limitations.

Bitcointalk.org is a community based forum that any user can register for free in any country. People use these forums based on their interests and can rate each user around them in various ways. They should have earned the right to vote out of respect for the forum contributors all along, right?

If they don't get 50 merit, maybe OP should also count them as valid votes because maybe they also have a clean heart to show respect to the users of this forum as I'm sure no spammer or cheater would dare to enter the meta for merit purposes.