Some of you might have read the article from Jonathan Zdziarski where he states that all your personal data is still on the iPhone after you have restored to a new firmware.
For the people who haven’t read it i’ll quickly explain.
When you restore your iPhone through iTunes, all it does is a quick format.
This means that all your data is still on the iPhone although no longer in the partition table.
If you use Jonathan’s iPhone Forensics Toolkit, it’s not that hard to get all the data back in the open.
This means that all your pictures, e-mails, cookies, etc,etc are visible to the next person who is going to own your iPhone !
» Securely wipe your iPhone the guide !