You should wipe all the data from your iPhone and return it to factory conditions if you are giving away, selling, or recycling an old iPhone.
Hosted on MSN

How to Erase your iPhone

Want to erase your iPhone? If you are selling your iPhone, Trading in your iPhone for a newer one, or giving your iPhone as a gift, you should fully erase your iPhone. You can set your iPhone to ...
Deleting an app from your iPhone may seem like a straightforward process, but ensuring that all traces of the app and its data are completely removed can be more complex. The video below will walk you ...