Worried about an ADB-savvy thief stealing the precious data off your stolen phone or tablet? Well, Android 4.2.2 makes doing that a little harder now, with the addition of a USB debugging whitelist feature into the OS. The way it works is pretty simple - when you connect your PC to your Android device via USB, Android gets your PC's RSA key (an identifier token). In Android 4.2.2, when you have USB debugging enabled, this now causes a prompt to appear on connection, seen below.
The prompt asks you to confirm that you wish to allow USB debugging from the connecting PC, and allows you to add it to a whitelist such that the prompt won't ask you to confirm for that computer again.