Still, it's easy for criminals to find data on drives, even when they've been legitimately wiped clean, Moulton said. He buys used hard drives by the hundreds for his classes. These drives have been professionally wiped, but his students always find at least one drive in each class with information still on it.
That's because it's easy for a drive to get missed during the wiping process or improperly wiped. Compounding the problem, the software that some recycling companies use doesn't actually remove all data from the drive, especially data that may be hidden on corrupted parts of the hard drive known as bad blocks, he explained.
The surest way to get your data off of a hard drive is to physically destroy it, Moulton said.
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