Sailing stones, also called sliding or moving rocks is a geological phenomenon where rocks tend to move and leave long tracks into a valley surfaces like deserts without human or animal intervention.
If you dont't want that every time you take a picture with your Android device, it gets instantly uploaded to your Google+ profile, this tutorial's for you.
Apparently Google Glass lets you take pictures by only a wink gesture. It has a second little cam/sensor facing the person wearing it which is suppose to detect eye movement and blinking gestures.
If any file can not be deleted, then you can use the program LockHunter, which removes the active connections of other applications to that file, which allow you to change or delete file.