Banks and metals warehouses

What is going on with metals warehouses? The CFTC has subpoenaed banks and owners of metals warehouses to determine if there has been manipulation and fraud in the release and delivery of LME contracts. The banks bought warehouses to take advantage of financing opportunities in the metals markets, but in the process they have limited the amount that have left warehouses which may have resulted in the higher price for these metals. Slow deliveries may have cost the consumers and now the CFTC wants to get to the bottom of the issue. 

This has been on ongoing area of interest with highlights of the arcane rules in the NYT. Exchange rules and procedures for delivery matter.