Format the iPhone and wipe all the data completely?

For those advanced user, they may restore those refurbished iPhone and grab the previous owner’s personal data. In order to protect yourself before giving back the iPhone for repair or refund, you may try the following steps,

1. Restore the iPhone from iTunes.
2. On the “Info” tab un-check all options.
3. On the Photos, Podcasts, and Video tabs, un-check “Sync …”.
4. Create 3 big playlists at large as the storage capacity of your iPhone.
5. On the Music tab, select the first of your 3 playlists to sync. This will make the storage bar at the bottom looks full after syncing.
6. Sync your iPhone, change to the next playlist, sync again, and repeat one last time.

Since we do not have advanced recovery software, we cannot test it whether it works 100% or not. But, logically, this method will wipe the iPhone memory few times and will help to clean all the personal information stored.