Sure it is facile. But it is a burden and a exposure to risk, which wont be worthwhile for the most non profit blogs. And by the way, most blog comment systems

Sure it is facile. But it is a burden and a exposure to risk, which wont be worthwhile for the most non profit blogs. And by the way, most blog comment systems don't require you to create an account before commenting. So this "have them post a comment using their credentials" wont work anyway.