Android may be putting its users at risk with inadequate factory reset

Do you know that your Android device data can be restored after wiping?
Android is the most widely-used phone and app software in the world, with major manufacturers including Samsung and HTC using it as an operating system for their phones and tablets.  Now the operating system has shown a major defect; Android device data (pictures,videos, text messages, emails, details and data from third party app) can be restored after wiping or factory reset.

This means that people who have given away, sold or lost phones are now at risk of having their personal details and private or sensitive information in messages or emails seen by whoever now has their old phone. Over 500million users or previous users are at risk of data theft.
A report by Cambridge University revealed this after testing various Android devices with Android OS 2.2 to 4.3.

Source: Dailymail