Before selling a used smartphone, most users take the time to erase personal data contained on the devices to prevent anything from falling into the hands of strangers. Most smartphones come with an option for doing this built right into the operating system, but a newly-discovered flaw in how Android handles the process could allow anyone to recover your personal information, including text messages, social media data, and a lot more.

How much more, exactly? According to researchers at security software maker Avast who purchased 20 smartphones from eBay, they were able to recover over 40,000 photos, 750 emails and text messages, and even a completed loan application. A few hundred contact entries were also pulled from the phones, and the original owners of four of the devices were found using the recovered information. That’s not even the worst part…

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