Privacy issue on PPC

[Stingray]

Hey Guys,
I have a question Lets say that I just bought a PPC, I loaded all sorts of personal information like Contacts, passwords, Ect. Ect. Now 6 months later my PPC carps out one me. Lucky me that I signed on for insurance! Insurance company says “No problem Sir, we will ship out the replacement, just mail us the original one back”. I get my new set, Hard reset the old one and send it back. Now, the question is that what good is a hard reset? Can they still extract out my personal information even after it being deleted? I have done this myself with old hard drives that were formatted! Can this be avoided?