Hobby: buying used hard drives on eBay and unerasing the data for fun

My friend Simson Garfinkel wrote a great piece on the foolishness of selling hard drives that haven't been sanitized:

"Since then, I have repeatedly indulged my habit for procuring and then analyzing secondhand hard drives. (...) Last summer, I started buying drives en masse on eBay.

"In all, I bought and analyzed the content of more than 150 drives(...) In fact, only 10 percent of the drives I purchased had been properly sanitized.

"Much of the data we found was truly shocking. One of the drives once lived in an ATM. It contained a year's worth of financial transactions—including account numbers and withdrawal amounts—from a organization that had a legal requirement to not divulge such information. Two other drives contained more than 5,000 credit card numbers—it looked as if one had been inside a cash register. Another had e-mail and personal financial records of a 45-year-old fellow in Georgia. The man is divorced, paying child support and dating a woman he met in Savannah. And, oh yeah, he's really into pornography."