Does this sound like a silly question? The German Bundesbank doesn't think so. It has ordered an audit of their gold reserves, some 3,300 tons or so (1)(2)(3), which are stored in various vaults around the world. The key to this kind of request is not only the nature of the request, but the timing. People in business know that timing is everything. Stated another way, this gold has sat in these vaults for 50 years or so - why ask for an audit now when there has never been an audit done before? There is some recent concern that is giving someone the idea that gold should be checked upon now. The bank intends to melt down part of their gold and reform ingots with it, which is testing for the purity of bars received. This adds another dimension to the scenario. Not only do they want to know whether the gold is there, they want to know whether the gold has been tampered with.
Since this is the Bundesbank and not just anyone, it is something to be mindful of. If they are concerned, most people should be. If you think this request is isolated and based on paranoia, this same request was done by also Hugo Chavez recently.(5) He has the same thinking as the Bundesbank and repatriating his gold to his home country. There is also the story of fake gold bars being sold to the Australian mint by the Chinese.(4) Yes, these are small bars, but the point is that fake gold bars have been produced before.
Why does this matter to the average person? Gold may become the foundation of currencies in the near future. Should gold stored by central banks go "missing", "be tampered with", "have irregularities" or "variations" for purity, this implies that the currencies people are using may be backed by fraudulent material. If you purchase gold in ETFs, there may be a scandal where the ETFs are holding worthless metal, leading to a sudden writedown in the value of the unit. If you buy your own gold and it is fake, you have essentially been robbed by a counterfeit. If this can happen to a central bank, this can happen to anyone.
What to do? Like any other crime, be aware of what can happen and keep an eye on the current state of events. The odds are that most gold will not be defective. Do you use cash? There is counterfeit cash isn't there? The same can be said for copied credit cards, phishing scams, or dubious companies. The products are still used and life goes on regardless, but a layer of awareness and caution will help. The irony is that gold is designed to make currencies honest by making the printing of money accountable.
Disclosure: I have no positions in any stocks mentioned, and no plans to initiate any positions within the next 72 hours.