It's an OS issue, not a medium issue. That is, any storage medium is a risk. USB is particularly interesting because a single USB device can turn into a hub or

It's an OS issue, not a medium issue. That is, any storage medium is a risk. USB is particularly interesting because a single USB device can turn into a hub or a completely different device at runtime. So you can have a USB flash drive suddenly become say a keyboard and start typing stuff in.