this interview was posted today:

Cook: How much is left in unreported inventories that can come into the market?
Butler: Unless you have Superman’s x-ray vision and can see all the world’s vaults simultaneously, there is no way to know how much is left in unreported inventories. And I guarantee that you will make yourself crazy if you persist in trying to figure out the amount remaining.
Cook: Are you still sane?
Butler: No one comes with a butterfly net.
Cook: How much is known or in the reported category?
Butler: Since 2006, more than 550 million ounces have been transferred from unreported silver into reported world inventories, including the SLV and all other similar programs. Currently there are more than 716 million ounces in total world visible silver bullion inventories. That’s a very big chunk of my long-time estimate of one billion ounces in total world inventories. The way to look at it is that there are 550 million ounces less that can be transferred in the future. The long-term rise in price would seem to confirm my thinking.
Cook: Could the big shorts be buying the SLV to cover their short position?
Butler: Sure, but not to excessive amounts, as that would require lying to the SEC on ownership disclosure regulations. That’s not likely.
Cook: How much silver do you think JPMorgan and one other bank are short?
Butler: As of this moment, I’m guessing JPM may now be below 25,000 contracts. That’s 125 million ounces. But we won’t know for sure until more CFTC data are released.
Cook: How about the big eight shorts?
Butler: My guess is they are down to 56,000 contracts. That’s 280 million ounces.
Cook: How about all the shorts combined?
Butler: In COMEX futures total, I’d guess a bit under 500 million.
Cook: How does that compare with other commodities?
Butler: Still way off the charts when comparing paper contracts to real world production and inventories.
Cook: Do you see this leading to a price explosion in silver soon?
Butler: It’s one of several things that will lead to an explosion.

http://news.silverseek.com/SilverSeek/1290625106.php