I'm not sure about photos in camera roll; but you better make a backup yourself, as they can be easily copied out from the phone.
And, it will be very difficult to copy music/photo/video out from iPhone, as they are all separated and stored in random folder with random names.
You can try use iFunBox, there's a function to search for music files in your iPhone.
Photos are all stored in \var\mobile\Media\Photos\Thumbs\
Videos are all stored in \var\mobile\Media\Photos\Videos\