A lot of people are talking about a recent article posted by CNet which deals with the data left behind when performing a factory reset on an Android Phone.  Having used the forensic software listed in the article and recovering data myself, I don’t have any doubts the article is very true.

If you are getting rid of an old Android phone, I suggest you first encrypt it, then reset it.  That way any data recovered after the factory reset will be encrypted anyway.

Here is a link to an article showing you how to encrypt data on an Android Phone – http://www.howtogeek.com/141953/how-to-encrypt-your-android-phone-and-why-you-might-want-to/

Here is the original CNet article – http://www.cnet.com/news/android-phone-wiping-fails-to-delete-personal-data/