I can't find it now but a few years ago there was an article on zerohedge I think about some gold etf or bank who had done a photo op with 'their' gold in the vault to 'prove' that they did in fact have it, but the kicker was that the gold bar number was visible and sleuths found that it was listed on a different institution's gold bar list. How many 'owners' does each real bar really have?