IT researchers in
This means that all your text messages, emails, pictures, videos and Facebook password are remain in the memory of your phone.
The researchers tested 21 phones produced by HTC, LG, Google, Motorola and Samsung and they found out that all the information –Google account, conversations on massaging, etc are easy to recover, as nothing is lost or erased.
Thus, before you have decided to sell your phone be sure that you are not selling all your private information.