AutoPlay feature of the USB device on Windows can be quite dangerous. It is certainly more convenient to have Windows immediately pick-up the USB device once you plug it into the USB port. No matter how careful you are, it is quite possible that your USB device could pick up a virus or if you allow others to use your computer it is more probable that the USB device that they might be plugging into your computer could contain viruses and all sort of nasty things, who knows!