A hard disk bought from eBay contained launch procedures for a ground to air missile launch system.
According to the BBC, researchers from BT and the University of Glamorgan bought disks from the UK, America, Germany, France and Australia. They then examined these disks to see if they contained sensitive data.
How hard is it to analyse second hand disks? According to Professor Blyth from the University of Glamorgan, "It's not rocket science."