When Siciliano looked at the used and supposedly purged smartphones he bought as part of his test, he discovered that phones using Google's Android operating system in particular still contained personal data, including names, home addresses, security passwords and email login information, even though the owners claimed they had followed the factory-reset procedure.
The non-Android smartphones he bought, including BlackBerrys and Apple iPhones, did appear to have all personal data deleted when owners performed a factory reset and removed the cards that store sensitive information.
"If I had an Android phone, I just wouldn't sell or donate it," Siciliano says. "It's just not worth the risk. If I was going to recycle it, I'd take a hammer to the device first."
