iTunes by default automatically sync whenever your iPhone, iPad or iPod Touch is connected to your computer, sometimes it may delete your files too while syncing as per the settings configured. Whenever iTunes syncs with any apple device and if it is going to delete some data on your apple device it will first warn you and ask you a question with yes or no type message prompt.
Still, many new users gets confused with these questions asked by iTunes while syncing and a simple wrong click can delete all data on your apple device then you are left with no way to get that data back, except you can restore from the previous state backup copies of data while syncing already with iTunes.
In order to get away from this problem and stop iTunes to automatically sync you can use a free software called Sync Blocker which can Block iTunes from automatically syncing and deleting your media when you plug your device into your computer. Choose the version below to match your version of iTunes.
This application is portable so you don’t need to install, and it is available for both windows and mac os, however it works for the latest version of iTunes 9.1.1 released till now. However if you have iTunes version older than 9.1.1 still you can get a compatible version of this application, but after lot of searching on the developer website we could figure out how to get it.
Note: When you use this software, make sure that your that your apple devices are not connected to your computer via USB cable.