In a study conducted by Blancco, a leading data erasure and IT asset disposition solution provider, it was found that second-hand Android phones still retain data after a factory reset. The study was part of the European Union-funded SustainablySMART project.

In the first study, 100 Android smartphones were purchased from IT asset disposal (ITAD) operators in Europe. All the phones had undergone a factory reset on the ITAD premises. The study aimed to find out if these devices still held data from previous owners. The sample consisted of Android OS versions from 2010 to 2016. During the analysis, data was recovered from 19% of the phones, with 8 of them having critical personal data, and one having critical corporate data.

In the second study, the team expanded on a recognized Cambridge study on Android’s factory reset performance, analyzing 68 popular phone models from versions Gingerbread to Nougat. The study simulated a user’s experience by populating the phone with multimedia files, SMS, contacts, email, and social media. After a factory reset, the team extracted memory via forensic tools and analyzed the results. Data was recovered from 20% of the phones, including some running old Android versions, as well as a device running Android 4.4. One of the best-selling phones in history running Android Lollipop was sent to an external data recovery lab, where SMS messaging data was finally retrieved.