Mobile devices usually provide a “factory-reset” tool to erase user-specific data from the main secondary storage. 9 Apple iPhones, 10 Android devices, and 2 BlackBerry devices were tested in the first systematic evaluation of the effectiveness of factory resets. Tests used the Cellebrite UME-36 Pro with the UFED Physical Analyzer, the Bulk Extractor open-source tool, and our own programs for extracting metadata, classifying file paths, and comparing them between images. Two phones were s...