Selling used hardware with a storage aspect is always a risky proposition. Sure, you formatted that hard drive, securely erased the SSD or factory reset your Android device before parting with it on eBay or Craigslist but did the process actually work?
A recent study from security software vendor Avast may make you think twice, especially if you're dealing with an Android smartphone. As part of the study, the firm purchased 20 used Android handsets on eBay with the intent of seeing what sort of data they could scrape from previously owned devices.
The results are a bit alarming.
Among the recovered data included some 40,000 photos (yes, some were nudes), 750 e-mail and text messages, 250 names and addresses and even a completed loan application. As VentureBeat points out, one of the phones had some sort of security software installed but it was this handset that gave up some of the most valuable information of the lot.
Avast was not only able to identify the previous owner, they gained access to his Facebook account, gathered where he had been using GPS data and found contact information from more than a dozen of his closest friends and family. The guy also apparently had an appetite for kinky adult material.
Keep in mind that all of this was gathered from phones that had been wiped / factory reset. Ouch.
The problem is that when you delete a file, it's not really gone. All you're doing is erasing the data that points to the file and marking the space as available. Until that space has been overwritten, the information stored there can be recovered.