Forensic examination of secondhand disks

Used hard disks bought on an online auction site were found to contain personal and proprietary data. Some of the drives that had supposedly been erased yielded their secrets to forensic examination techniques. Others still had the original undeleted data and could have been read easily by any purchaser. The Irish newspaper article notes that homeworkers were probably the source of at least some of the security lapses, having used their own PCs for work projects, "forgotten" about the sensitive work data they contained, and sold the disks or whole systems privately. This kind of breach would fall outside the remit of most organizations I have worked for, except those few who insist that staff only use company systems for work activities, typically providing laptops for the purpose. That said, whether the laptop hard disks were properly erased at the end of their life, or the extent to which employees complied with the company policies on not working on personal IT equipment, is anyone's guess.