Root required for this application!
If you have a rooted phone and you have debugging enabled on your device then your device is at risk for attack!
This project: https://github.com/kosborn/p2p-adb/ provides a set of tools for attacking your device from another device if you have debugging enabled on your phone.
Here is a video showing what this application helps protect you from: https://www.youtube.com/watch?feature=player_detailpage&v=ah7DWawLax8#t=429s
This application can help guard against this in conjunction with a password, pin, or pattern protected device. For this application to work and be effective you must have a lock screen enabled password, pin, or pattern lock.
This application will turn adbd on when the phone is unlocked and will turn it off when the screen goes off.
This application works with Tasker, you can use Tasker to enable and disable adbdSecure on a wide variety of different conditions.