A new way to vote in a social news site

The submitter includes a question with the submission.

Only those who get the question right may upvote/downvote the submission.

The challenge for the submitter is to come up with a question that upvoters would tend to get right while downvoters would tend to get wrong.

This motivation would probably restrict voting to only those people who know something about the submission topic.

This might be a good way to handle voting in a forum with wide scope.