This set of scripts is experimental
With these scripts you can filter which USB devices can connect to your linux
system. For instance, allow your usb mass-storage device only to be exactly
that and not one day register itself as a keyboard...
"AllowClass" is the usb class code . For example, use 08 for usb flash drives.
Add the following to the kernel command line (edit your boot loader config): usbcore.authorized_default=0
Make sure the following runs by init on system boot:
echo 0 > /sys/bus/usb/drivers_autoprobe
echo "/sbin/hotplug_filter.sh" > /proc/sys/kernel/hotplug
Use scan_new.sh to see devices which aren't in the whitelist yet.
 List of classes: http://www.usb.org/developers/defined_class