Well, according to Dr. Morse, cacao is highly acidic and has a high oxalic acid content. Dr. Morse states that when your body is acidic and you consume foods that are high in oxalates, these oxalates bind with ionic calcium causing calcium oxalate stones, such as kidney stones. I think it's okay to eat small quantities. I do have David Wolfe's book on Superfoods and Chocolate.

I highly recommend buying Dr. Morse's book. I did see someone take an older version of his book and converted it into a PDF online.