I doubt that there any naked shares sold short. If there have been, the MM's have been covering and there have been no 'fail to delivers'. Additionally, there havn't been any shares sold naked here since November of 2007.
Short interest (short selling and covering) vs total volume since sept. 5th thru 12th.
September 12, 2012
2,373,500 - 2,833,500.
September 11, 2012
400,939 - 895,272.
September 10, 2012
150,000 - 356,299.
September 7, 2012
298,500 - 1,151,925.
September 6, 2012
755,000 - 1,128,990.
September 5, 2012
85,000 - 273,750.