It's standard practice to factory restore an Android device before flipping it on eBay or Craigslist, but the amount of recoverable data you leave behind might shock you. Those nude selfies that were only intended for your special friend? They're on there, and so is a wealth of other personal information that security firm Avast claims can be "easily retrieved" from used smartphones sold online.
Avast isn't talking out of its backside, either. The security outfit proved its point by analyzing 20 used Android smartphones whose previous owners had successfully completed a factory reset or "delete all" operation. Despite the safety precaution, Avast was able to extract a dizzying amount of information.
We're talking about more than 40,000 stored photos, of which there were over 1,500 family photos of children, 750 photos of women in various stages of undress, and 250 male selfies showing off their manly bits. On top of the photos, Avast uncovered more than 1,000 Google searches, over 750 emails and text messages, in excess of 250 contact names and email addresses, four previous owners' identities, and even a completed loan application.
"More than 80,000 used smartphones are for sale daily on eBay in the U.S. Along with their phones, consumers may not realize they are selling their memories and their identities," said Jude McGolgan, President of Mobile at Avast. "Images, emails, and other documents deleted from phones can be exploited for identity theft, blackmail, or for even stalking purposes. Selling your used phone is a good way to make a little extra money, but it’s potentially a bad way to protect your privacy."
This is bit of a self-serving study on Avast's part, though not necessarily to sell you anything. If you're planning to list your Android device online, Avast suggests you first install its Anti-Theft app and use the thorough wipe feature to permanently nuke your data and overwrite all files. The free app is available on Google Play.