A fifth of secondhand PCs finding their way onto the resale market still contain sensitive data on their hard discs. Research by BT, the University of Glamorgan in Wales and Edith Cowan University in Australia, has found that while 41% of the disks were unreadable, 20% contained sufficient information to identify individuals. The research, based on the acquisition of 300 PCs from auctions, computer fairs and on-line purchases, also found that 5% of the machines held commercial information on organisations, and that 5% held