The best way to do it according to the article, is to “encrypt” the phone first. Then do a factory restore on it. I believe Android added in encryption in Gingerbread (2.3). So most phones can do this. Why not just do the factory reset. Well that doesn’t really work as many researchers have found out by getting used phones and digging into them.
http://www.ubergizmo.com/how-to/wipe-android-phone-tablet/?utm_source=mainrss
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